Katie Price was oblivious to Kieran Hayler and Jane Pountney's flirting.
The former glamour model - who recently discovered her husband was having a "full blown sexual affair" with her married best friend - didn't pick up on the spark between the pair, according to a house guest.
Jemma Henley - who spent four months at their home - told The Sun newspaper: "To get attention she would laugh at Kieran's jokes and stroke his arm - you could cut the sexual tension with a knife.
"There were looks that went unseen by Katie - but I didn't miss them. How she didn't see this coming is beyond me. Jane was always giggly around Kieran and she didn't try to hide it.
"But if there is one person Katie trusted it's Jane - she could do no wrong in her eyes. Maybe she left them alone one too many times. Jane was once me she liked his muscles."
Jemma explained how Katie and Jane were "like sisters", but thinks the star's bridesmaid was influenced by "jealousy".
She said: "There were like sisters. If there is one person Katie would die for it's Jane. I really feel for Katie in all this.
"These are the two people closest to her. This is the ultimate betrayal ... Jane has lived in Katie's shadow for 12 years - that's a long time to play second fiddle.
"She was jealous and that has led to her bedding Kieran."

Manic Street Preachers will keep performing until they are in "wheelchairs".
The Welsh trio - who formed in 1989 - don't think any younger bands have emerged who can "replace" them so they can't ever see themselves retiring.
Bassist Nicky Wire said: "I think the reason we're still around is because there's never been anyone to f***ing replace us - no one to make us extinct...
"I think it's full-on, blasting rock 'n' roll from now on, until we literally have wheelchairs."
The 'Motorcycle Emptiness' group - who release new album 'Futurology' on July 7 - also admitted they occasionally felt "awkward" when promoting last year's largely-acoustic 'Rewind the Film'.
Frontman James Dean Bradfield said: "It pushed us to be delicate and intimate and earnest and all those things we'd never really been.
"It didn't come naturally, it was really awkward at times."
The band - which also includes drummer Sean Moore - say that, with 'Let's Go To War', one of the tracks on 'Futurology', they wanted to create another "f***ing angry" song.
Nicky told NME magazine: "'Let's Go To War' has implications of the crisis of the working classes in it, but it's also referencing us as a band. Let's have one last f***ing angry song, like 'The Masses Against the Classes' or 'You Love Us' that references our own desire to lay waste."

Carey Mulligan returned to theatre because of the lack of brilliant female roles in film.
The 28-year-old actress is returning to London's West End after a seven-year hiatus to star alongside Bill Nighy in a revival of playwright David Hare's 'Skylight' and she admits it's because she couldn't pass up the chance to take on the lead.
She said: "There are so few brilliantly written female characters out there and she's such a great opportunity."
Since her last theatre appearance in 'The Seagull' in 2007, the 'Inside Llewyn Davis' actress has won numerous awards for her roles in films such as 'An Education' and 'Never Let Me Go', but she's confessed the storyline of 'Skylight' persuaded her to return to the stage.
She explained: "I was drawn to the intimacy of it, and how it was so focused on one conversation and how two people who have history both see the same event.
"The challenge of filling that stage for one and a half hours, going head to head with one actor and of having to find new experiences with the same material night after night and figure out more stuff about it. It's very exciting."
However, as Mulligan has also been busy working on her new film 'Suffragette' alongside Meryl Streep, she's confessed she hasn't had time to stress over her return to the stage.
She added to Britain's Vogue magazine: "I've been so wrapped up in the film I haven't really thought about 'Skylight', which is probably a good thing because I haven't been worrying about it."

Kate Upton knew she'd become a megastar when she gained female fans.
The Sports Illustrated model has become a household name following cover shoots for the magazine and a role in recently-released comedy 'The Other Woman' and she admits she knew she'd really made it when she started to gained female followers as well as male ones.
When asked to pinpoint the exact moment she became a megastar, she said: "I think it was kind of how everything was placed at once, in a weird way.
"I had Sports Illustrated and that next year I worked with Vogue and it was really just the placement of things. One year I had a lot of male followers, and the next, women followers and fans. I didn't have a say in it - that was just how it went."
The 21-year-old star faced disapproval from figures within the fashion industry for being "too curvy", but admits now that she's overcome the criticism she feels at home in her job.
She told Britain's Vogue magazine: "Once you're in the fashion crowd, it's almost like a family. They're so loyal and so supportive, and I talk to most of those people on a daily basis."

Mila Kunis is reportedly struggling with morning sickness.
The 30-year-old actress is said to be pregnant with her first child with her boyfriend, and rumoured fiancé, Ashton Kutcher, and although she's struggling with nausea, he's said to be helping her through.
A source said: "Mila's been suffering from morning sickness and is feeling exhausted, but she says Ashton has been her rock. He's been cooking her breakfast in bed. He's even hired a masseuse to give her daily massages and, at night, he rests his head beside her bump and talks to the baby."
Reports have suggested that the 'Friends with Benefits' star is expecting a baby girl with Ashton - who she first met on the set of 'That 70s Show' in 1998 -and although she's struggling with the side effects of pregnancy she's said to be happier than ever.
The source told Britain's Closer magazine: "Mila's so excited to be a mum, she's telling friends her and Ashton are more in love than ever."
The Hollywood couple are also reportedly looking forward to expanding their brood once their first baby is born.
The source added: "Ashton can't wait to be a dad; he's always wanted children. Mila wants at least four and he's keen too."

Rita Ora was "scared" when she met Beyonce.
The 23-year-old singer - who signed with Jay Z's Roc Nation in 2009, the same year she made a cameo on the rapper's 'Young Forever' video - was thrilled to finally meet her label boss' wife and insists she was more amazing than she'd anticipated.
She told Heat magazine: "Oh my gosh, I was so scared. She's like the idol I've always wanted to meet. I always thought she wasn't human and that she just plugged herself into a socket at night and sleeps standing up, or something. But she was incredible - so kind, so honest, so caring and so approachable."
Rita has landed her big Hollywood break with a role in the most-anticipated film of the moment, the adaptation of kinky bestseller 'Fifty Shades of Grey', in which she plays S&M-loving billionaire Christian Grey's little sister Mia.
However, the platinum blonde bombshell recently insisted things weren't hot and heavy on set because leading actor Jamie Dornan is such a down-to-earth family man.
She said: "No, it was incredible, cause his wife was there and he just had a kid so it was a very family orientated kind of thing, obviously when it's on set the kid stays at home."

Binky Felstead claims she suffered "horrific" bullying at school.
The 'Made In Chelsea' star - who was educated at Dallington School, Taunton School and Millfield in Somerset - reveals her life was made miserable by her childhood tormentors in her new autobiography 'Being Binky' but she was able to beat them and eventually get the "last laugh" with her TV fame.
Speaking to BANG Showbiz, she said: "In the book I try and educate people on how to deal with bullies at school - because I went through that when I was growing up and it was very difficult. I'm basically saying speak out about it, don't try to keep it all in because it will end up torturing you, and you do get through it in the long run. The bullies at school were horrific but they've all messaged me now and I've got the last laugh."
Binky managed to cope with her bullying with the support of her mother and the help of a counsellor, and she hopes her book will be able to help any teenagers dealing with the same problem.
She added: "The book is all from personal experience, from how I got through it ... I would have liked to have read my book if I was going through what I was going through at a young age because I didn't realise bullying was mainly to do with jealousy, and I didn't realise it was OK to speak to a counsellor that young because not many people my age did. It's incredibly important to be able to vent to someone, and if you can't do that with your mum, you should think about speaking to someone professional. I'm lucky that I have a great relationship with my mum."
Binky will be at Waterstone's, Bluewater on Saturday May 10 at 4:30pm signing copies of her new book 'Being Binky', which is available through Simon & Schuster.

Chris Brown has been sentenced to 131 days in prison. The 24-year-old singer has been forced to spend just over four months behind bars after he admitted in a Los Angeles court today (09.05.14) that he violated his probation by getting into a fight in...

Jordin Sparks admires her mother's "inner strength".
The 24-year-old singer, who has been dating Jason Derulo for just over three years, admits she looks up to her mum Jodi Jackson because she's an inspiration to her.
Speaking to PEOPLE.com, she said: "It's her inner strength and courage. When I was about 12, she told me not to lock my bedroom door. But I did. What did she do? She took my door completely off! It wasn't like she said, 'You're in trouble,' it was, 'You have no door for six months!'"
The 'Battlefield' hitmaker - who shot to fame after winning 'American Idol' when she was just 17 - insists it was her mum who encouraged her to pursue a career in singing.
She explained: "We were watching 'American Idol', and I said, 'I want to do that.' And she said, 'We will do whatever it takes.'"
Meanwhile, Jordin, who also works out with Jodi, has recently lost 50lbs after deciding she needed to make changes to her lifestyle in order to improve her health.
She said previously: "I had gotten really sick. And I was about to celebrate my birthday and I was like, 'I should be in the prime of my life right now. I shouldn't be feeling like this. I really need to make my health a priority'."

Elizabeth Olsen isn't thinking about having children yet.
The 25-year-old actress is planning to get married to her fiancé Boyd Holbrook, 32, in the near future, but she insists starting a family isn't on her mind at the moment.
She told E! News: "I'm not really thinking about kids. I think, like, you just take it one step at a time in your life, I guess. I love working with kids in films. It keeps you on your toes in such a way that you can't expect anything from them and you have to have patience and be creative."
Meanwhile, the brunette beauty, who got engaged to her beau in March, has been busy making arrangements for her big day and creating "fun" plans.
She said previously: I'm relaxed about it [the wedding], but I am excited and planning ideas because it's fun - It's just like throwing a party to celebrate life. I love being in a relationship a lot."
Boyd reportedly popped the question just two weeks after Elizabeth's older sister Mary-Kate, 27, got engaged to her boyfriend Olivier Sarkozy, 44, but she insists she won't be having a double wedding with her sibling.
When asked if she and Mary-Kate were planning on having a joint ceremony, Elizabeth replied: "No, I just told her she gets to pick a date [for her wedding] first!"

Taylor Swift believes her friendship with Selena Gomez is the "longest" they've both ever had.
The 24-year-old singer insists she shares a special bond with the 'Come & Get It' hitmaker because they've both been thrown into the limelight at such a young age.
She told E! News: "It's been the longest one [friendship] I think either of us had really. When your life changes and you become thrust into this really strange whirlwind where what your life is is different from what other people think your life is. And your life is commented on and your life is written about and fictionalised and all that. Both of us have kind of stuck it out and hung in there through all the different changes we've gone through.
"Longevity is something you really can find very precious and rare in friendships."
The blonde beauty recently admitted that she only hangs around with genuine people - such as Selena and Emma Stone - because they help her stay grounded.
She said previously: "I don't want people around me telling me what they think I'd like to hear. I love being surrounded by friends who are brutally honest and genuine.
"[We talk about] everything, except our work! It's always about reconnecting with each other, talking about relationships, love and guys - all the basic things!"

Claudia Winkleman will replace Sir Bruce Forsyth on 'Strictly Come Dancing'.
The BBC have confirmed the 42-year-old presenter will join Tess Daly as the host on the TV dancing competition after Bruce announced earlier this year he was stepping down after 11 series on the popular programme.
Claudia said: "I have loved 'Strictly' since the second it appeared on our screens and I am honoured and thrilled to now be part of the Saturday night team.
"Working alongside Tess is always fantastic and I can't wait to spend the weekends with her, our amazing dancers and the greatest judging panel on the planet. Sir Bruce is a living legend and we'll all miss him very much."
However, Bruce, 86, won't be hanging up his dancing shoes permanently as he will be reuniting with Tess for Children in Need and Christmas show specials.
Tess added: '"It's really exciting having two women host the show, and we are great mates so there'll be lots of fun to be had on and off the dance floor, and of course I'll look forward to being reunited with Brucie for the Children In Need and Christmas shows.''
Claudia was the hot favourite to replace Bruce after he announced his departure as she has been involved with 'Strictly' since 2004 when she fronted 'Strictly Come Dancing: It Takes Two' to coincide with the second series of the main show.
In 2010, she also took over from Bruce as co-host of the Sunday night results show.