Daniel Radcliffe finds his girlfriend's passion for sport "sexy".
The 'What If' actor loves the fact Erin Darke is as big a fan of NFL as he is and finds it fascinating being able to discuss the game with her.
He admitted: "She's an obsessive Detroit Redwings fan - when your girlfriend can talk s**t about sports better than the men she's doing that with, that's pretty sexy."
The 25-year-old actor also admitted he finds it hard to "surpress" his emotions and is always honest about his feelings for the opposite sex.
Asked if he is as hopeless as women as his 'What If' character, he told The Guardian newspaper: "No, I'm a lot better at being direct at things, I'm not good at suppressing that stuff. If I have a crush on a girl she's going to know about it."
The 'Harry Potter' actor prepares intensely for his movie roles and can't even watch movies or go to the theatre when learning a script as he just feels guilty about not being word-perfect.
He said: "I can't even watch plays or films when I'm learning lines. I start to think, hang on, they know all their lines and I don't ... so I have to go home immediately and learn them."

Coleen Rooney snubbed husband Wayne Rooney's first game as Manchester United club captain to party at V Festival instead on Saturday (16.08.14).
The 28-year-old star headed to the music extravaganza at Hylands Park in Chelmsford, Essex, on the weekend to let her hair down with a number of female pals instead of supporting her other half at Old Trafford, Manchester, where his team suffered a dismal defeat to Swansea.
Despite Wayne scoring United's only goal of the game, he couldn't inspire the team to a victory in his first game as official club captain on a full-time basis following the appointment by his new manager Louis Van Gaal.
While Wayne and United were struggling on the pitch, Coleen was having a wonderful time in Virgin Media's Louder Lounge VIP area at the festival, 221 miles away from Old Trafford.
She was said to have left her and Wayne's children Kai, four, and 14-month-old Klay with her mother in Liverpool as she made the trip down south past V Festival's other Staffordshire location to the Essex site.
Despite missing Wayne's big moment, the star - who took the couple's sons to Brazil during the summer to watch their footballer dad play for England in the World Cup - did manage to get on Twitter to show her support to her husband.
Before United's game against Swansea, she tweeted: "Good luck to @WayneRooney .... First premiership game as Captain!!! (sic)"
A number of other stars also made it into Virgin Media's Louder Lounge area including 'Skins' beauty Kaya Scodelario, Katherine Jenkins and The Saturdays' Vanessa White.

Sylvester Stallone is preparing to appear in 'Rambo 5'.
Stallone, 68, recently starred in the third instalment of the 'Expendables' franchise - in which he appeared alongside the likes of Harrison Ford and Jason Statham - and he's already working towards starring in 'Rambo 5'.
He said: "I'm getting ready for 'Rambo 5'. I'm starting to work out. I'm going to be appropriately vicious and all that stuff, but intellectual.
"A killer with a heart. Smart, yet stupid. Tall, yet short. Broad, but thin. You know what I mean. We're going to try to cover all the boundaries."
The fifth 'Rambo' film will see the central character - played by Stallone - face off against a Mexican cartel, with the action hero having previously described the much-hyped flick as his version of 'No Country for Old Men', the neo-Western thriller starring Javier Bardem and Tommy Lee Jones.
There is also the expectation that Stallone will prise the role of boxing champion Rocky Balboa in a new movie called 'Creed', which will see the iconic character mentor the grandson of his rival-turned-friend Apollo Creed.
The lead role in the flick is to be played by Michael B. Jordan, who is best known for playing the role of Wallace in 'The Wire'.

Ving Rhames is to return for the next 'Mission: Impossible' movie.
The highly-anticipated new flick, which is set to get underway in the UK later this year, will see Christopher McQuarrie assume directing duties and Rhames, 55, reprise the role of hacker Luther Stickell.
The news was confirmed by the director, who tweeted: "Welcome back Mr. Rhames."
The actor, who also starred in 'Pulp Fiction and 'Dawn of the Dead', appeared in earlier 'Mission: Impossible' films, and will now feature alongside Hollywood superstar Tom Cruise, as well as Jeremy Renner and Simon Pegg.
Pegg, 44, who is set to play the role of gadget nerd Benji Dunn for the third time, says he enjoys making the films and providing there is still an appetite among fans to watch them, the franchise will not go away.
He said: "It's my third one and I'm very excited to be back on that train, it's a very exciting ride.
"So as long as people want them, I guess we'll keep making them."
It's been confirmed the latest instalment in the Mission: Impossible' franchise will open in the UK on December 26, 2015.

The Killers brought V Festival to a close in sublime style last night (17.08.14) by bringing Jimmy Carr on stage to introduce their encore.
The 'Somebody Told Me' hitmakers - who were playing the event for the fourth time - invited the comedian on stage at Hylands Park, Chelmsford, Essex, to introduce their 2006 hit single 'When You Were Young'.
He told the crowd: "You have two options: You can call it a night, you might be fresher for work in the morning, or you could demand more?"
His first suggestion prompted boos from the audience but they were left cheering when he walked off stage with the returning band heading in the opposite direction following a short break at the end of their energetic greatest hits set.
That wasn't the Las Vegas band's only surprise of the night though as they also performed a superb cover of Iggy Azalea and Charli XCX's 'Fancy' resulting in drummer Ronnie Vannucci stepping out from behind his drum kit to pull off some suggestive dance moves while frontman Brandon Flowers sang.
But The Killers were not the only impressive act of the weekend as several other stars excelled at the festival.
Lily Allen got plenty of plaudits for her set on the main Virgin Media Stage but it was a wardrobe malfunction which stole the show as her plunging silver jumpsuit plunged a little too far leaving the bra-less star's assets on display for all to see.
Sam Smith continued his fantastic year by entertaining fans on the star-studded MTV Stage on Sunday, which also featured Rizzle Kicks, Tinie Tempah and Jason Derulo among other big names.
M People had got V Festival's Sunday off to the perfect start by rolling back the years with a greatest hits set and Train, Chic and Rudimental followed suit later in the day.
On Saturday (17.08.14), Ed Sheeran wowed the crowd with a selection of hits from his two albums and he later received a somewhat unexpected shoutout from Saturday night's headline act Justin Timberlake.
Following his performance of 'Cry Me A River', Justin told the crowd: "Brother from another red-headed mother Ed Sheeran - he's a bad motherf**ker!"
Other Saturday performers at the festival included Example, Kaiser Chiefs and Bastille.
A number of stars also made it into Virgin Media's Louder Lounge area including 'Skins' beauty Kaya Scodelario, Katherine Jenkins and The Saturdays' Vanessa White.
And when people weren't living it up in the Louder Lounge or taking in the fine selection of acts performing at the music extravaganza, some were having a fantastic time at the Lucozade Energy YES Arena.

The childhood home of Britain's Duchess of Cornwall is up for sale for £3.25 million.
Actor James Wilby - who starred in 'Gosford Park' - has lived in the seven-bedroom house in east Sussex for 18 years but has put the impressive abode on the market in order to downsize.
The 56-year-old star and his wife Shana, 55, purchased the property from Camilla's father Major Bruce Shand, who lived there for 45 years.
The plush pad is spread over three floors and features three bathrooms and a shower room as well as a separate three/four bedroom cottage.
James and Shana admitted they fell in love with the house when they first viewed it and he grew to love the wide lawns and secret garden.
He is quoted by MailOnline as saying: "We went from a flat in Notting Hill to this. We didn't know much about gardening when we arrived.
"As an actor you get time between jobs so I've been able to do quite a lot in the garden."
The abode also boasts large Georgian windows and high ceilings and features a farmhouse-style kitchen and a play room.
Camilla - who married Prince Charles in 2005 - once described her childhood home as "perfect in every way".

Chris Brown and Karrueche Tran have fuelled speculation they are back together.
The on/off couple - who were believed to have ended their three-year relationship for good earlier this month - were spotted together at a charity football game in Los Angeles on Saturday (16.08.14) and seemed more in love than ever.
Ahead of the game, Chris wrote on Instagram: "It's going down! Team Breezy vs. Quincy [Jones'] team (sic)"
The brunette beauty was seen cheering on the 'Turn Up the Music' singer from the sidelines, before they embraced on the field and were openly affectionate as they left the game.
Later in the evening, the 25-year-old singer posed for a selfie with the 26-year-old model as the drove through Los Angeles.
Their date day comes just over a week after it was claimed Chris dumped Karrueche because she was an "opportunist."
A source said recently: "He found out she was texting and sending photos to other guys while they were together.
"He was also furious she did interviews for her clothing line and talked about their relationship."
It was previously claimed Karrueche dumped the 'Loyal' hitmaker because he liked two fan photos on Instagram of himself and ex-girlfriend Rihanna - who he has been frequently re-linked with during his off periods with the model - together and is too "immature" for her.

Kate Moss partied with Madonna at her birthday party over the weekend.
The 40-year-old supermodel joined the 'Material Girl' singer in celebrating her 56th birthday at a lavish 1920s-themed celebration in a private villa in Cannes, France, where the pair were pictured cosying up together in revealing flapper outfits.
Madonna posted the photo of herself wearing a beaded black dress next to the iconic model - who was clad in an strappy black gown - on her Instagram account yesterday (17.08.14).
She captioned the image: "Bow down Bitches! #whatitfeelslikeforagirl.(sic)"
The 'Holiday' singer also shared a shot of partygoers posing in front of giant 'M' and intertwined with pink feather boas, who were clearly enjoying their evening.
She wrote: "House of M! House of Fun! La Vie en Rose! #unapologeticbirthdaybitch."
Madonna - who was joined the event on Saturday (16.08.14) by her children, Lourdes, 17, Rocco, 14, David, eight, and Mercy, also eight - also shared a picture of her youngest son looking dapper in a black tuxedo.
She wrote alongside the picture: "My escort for the evening! #swag #boom #livingforlove.(sic)"

Alexander Skarsgard wants to star in a Broadway show.
The 'True Blood' actor is currently househunting in New York and though he has no definite career plans once the vampire drama ends this year, he is keen to work on the stage.
He said: "I'm actually looking at apartments in New York now. I'm in London for another three months for Tarzan, and then my plan is definitely to move to New York.
"I'm really excited about it. I don't really have any plans in terms of what I want to do - movies, television, theatre - but I'd love to do a play in New York. Anything that would be a break from what I've been doing, something different."
Alexander is feeling "excited" about having a future with no definite plans.
He said: "After seven years on the show, where every break before was a hiatus from the show, there's something quite exciting about not knowing what I'm going to do next. It's a feeling I haven't had in seven years, and I'm pretty excited about it."
The 37-year-old actor is keen to do something "fun" next in his work after seeing how much his father, Stellan Skarsgard, enjoyed working on musical movie 'Mamma Mia!', and thinks he does his best work when he is having a good time on set.
He explained to Vulture: " I mean, my dad did 'Mamma Mia!', just after he had done a couple of dark indie films, and he had a really good time doing that. He loved it.
"He was like, 'F**k it! This is fun. This is different. There's nothing wrong with fun. I'll do it!' You know?
"It's all about trying to find those projects where you get to enjoy yourself, because I think that's when you create as well, when you're genuinely excited about something. Then you're not just doing it because it's your job."

Kid Rock is to be a grandfather for the first time.
The 'All Summer Long' hitmaker's son Bobby Ritchie Jr. - who he has with ex-girlfriend Kelley South Russell - is expecting a baby with his girlfriend, Us Weekly magazine reports.
According to the publication, 21-year-old Bobby's partner is already four months along and the couple will be welcoming a baby girl into the world.
The 43-year-old rocker - whose real name is Robert Ritchie - hasn't yet commented on the happy news.
The 'Born Free' star won a custody battle against Kelley in 2000, charging her $25 a week in child support and raising his son largely on his own.
And the singer - who was previously married to Pamela Anderson - has previously admitted to keeping his on stage persona separate from his family life.
He has said: "Make no mistake, Bob Ritchie's up early in the morning taking pictures of his son on the first day of his senior year. Kid Rock is passed out in a hotel room somewhere with four scantily clad women."
However, he has also confessed to refusing to hide the excesses of his rock'n'roll lifestyle from Bobby when he was young.
He said: "When Junior was young, it was Christmastime. I had a gig the night before, and I was s**t-faced, just beyond. Drugs and alcohol. I passed out in my bathroom, dead weight.
"My son comes in, he's like, 'Grandma, something's wrong with Dad!' So my mom tries to get me to make this big excuse up. 'Tell him you came home and you were tired and this that and the other.'
"I'm sitting there at breakfast and I say, 'Your dad got trashed last night.' I'm going to sit here and lie to this kid? He's like seven. I'm like, 'Big concert, party afterward, I drank too much and passed out. I'm not proud of it, but that's what happens when you do that.' "

Martine McCutcheon is pregnant.
The 38-year-old actress - who has battled depression - has announced she is three and a half months pregnant with a son, but admits she and husband, Jay McManus, had all but accepted they were never going to have a child together.
She said: "We'd always said that if we were fortunate to be blessed with a child, that would be wonderful, but we were very aware that it's not a given.
"As a woman in her late 30s who's experienced health problems, I thought I might have to accept that it wasn't a path my life was going to take, but it would have been a great sadness in our lives if that had been the case."
As well as battling depression, Martine has suffered further difficulties including being declared bankrupt in January last year, owing £187,000, but the raven-haired beauty believes her life is now fully back on track after discovering she is expecting.
She added to HELLO! magazine: "It's like finally the tides have turned. Great things are starting to happen on the work front, but more than anything, expecting our baby boy has given us clarity about what matters."
The star shot to fame as Tiffany Mitchell in 'EastEnders' in 1995 but she departed the BBC One soap in 1998 after her character was killed in a car crash.
Martine went on to appear in several movies including 'Love Actually' and 'Jump!' alongside the late Patrick Swayze, while her last notable acting appearance came in a 2013 episode of 'Midsomer Murders'.

Jackie Chan doesn't want violence or "dirty comedy" in his movies.
The 'Around the World in 80 Days' actor considers the films he directs to be like his children, and he has a very strict set of guidelines he makes sure he adheres to when working on a project and it includes stripping them of unnecessary fighting despite his martial arts background.
He told The Observer Magazine: "When I direct, the film is like my baby. I have to make sure there is comedy but no dirty comedy and a positive message.
"I like people to believe the stunts are real - it's not like 'Spider-Man' or 'Iron Man' where a 20-minute scene can be pure CGI. I only use a tiny bit of special effects.
"I want it to be believable, so where I used to do a triple kick, I now just do one. Eventually there will be no kicks. There has to be plenty of action, but not violence."
Meanwhile, Chan admitted even though his fame has come from starring in action films based on his martial arts skills, he actually has a real problem with "violence".
He explained: "I have a dilemma. I love action, but I hate violence. There is so much violence in the world, from video games and from other movies.
"I want my movies to have a message of peace, and helping each other ... You have to keep working and keep learning. If children are playing video games or lying in bed they won't."