How do you know when you're being cheated on?

I asked my mother this question in my teens, out of curiosity, and her reply was "you just know" and to this day, unless there are OBVIOUS SIGNS I have always wondered; HOW DO YOU KNOW?

An example of this is my best friends partner went on this business trip with various colleagues, one of whom had a very obvious crush on her partner for several YEARS, anyway, long story short, her partner told him that this woman had come on to him and he turned her down SEVERAL times, which she accepted as she does trust him. However, a few weeks after he got back, he told her that the woman in question told some fellow colleagues that they kissed etc and she even told HER partner. My friends partner denies this but she says she doesn't know what to believe.
As her best friend, she begged me for my judgement as in her opinion I'm good at judging characters and situations but I was totally stumped because I'm on good terms with them both - the only thing that is making me doubt her partner is after he got back, he apparently became very moody, and refused to be seen with her in public for almost a MONTH and this was apparently because he didn't want to be seen with her until she lost all of her weight (she's a UK size 12 btw) ! ! Then a month after that he apparently confessed that it was because he was worried that they might bump in to this woman, which made me suspicious but she reassured me that he said it was because he "knows" what my friend is "like" in terms of losing the rag etc.
However, my query is - if he didn't do it then why is he worried?


Sasha xx x

Just a thought

When your mother said that you'd just know she could have been meaning trust your instincts.
If you are finding yourself wondering about something then there has to have been a trigger to get you to start thinking.
Perhaps that would have been your instinct and that is when your mother thought you would just know.

Sus behaviour?

Now that you mention it, she did say that he has passwords on EVERYTHING - laptop,blackberry - the lot! And she mentioned while he was away he barely called etc and when his phone bill came in she opened it and there was a lot of calls to a number..that wasn't hers but he claimed that he had been too busy working to call. When she confronted him, he went mad, saying she had no right etc
He doesn't work late but he does go out a lot and before the trip they were talking of marriage in the near future where as now he apparently said he isn't interested in getting married until he is at least 40 (they're both 25) and children aren't really on the cards (even though she has always wanted at least 3 children, one day).
Also she has told me in confidence that when they argue, she plays the "you probably did sleep with that slut" and his response one day was "yes and she was a better lay than you" although he assured her that he just threw that in as a cheap shot, I was totally taken aback - and even I'm beginning to wonder if he is as innocent as he makes out in all of this. Also, this woman told several colleauges that they made out and that more was going to happen but that they were interrupted - as first myself and my friend thought "Well she has been obsessed with him for YEARS maybe she's making it up.." but not I just don't know and my friend as I know her is falling apart - she smokes a lot (she only took it up when this all came about), she barely sleeps and she generally has just lost a bit of her sparkle Thoughts? If he is or has cheated, how can we catch him out????

Hi

This is a difficult one, I think she would know if he was as they do start to act differently. Maybe out of guilt they either pull away from their partner, becoming more distant or acting strangely. But it could just be he was worried about what she would say to her if she seen her. I know personally from being cheated on by previous partners things like not holding hands in public or not wanting to go to a place where the mistress may be is a give away. Keeping their work life seperate from home life. Not wanting their partner to mix with their friends, always on the phone texting but they never talk about who it is and never leave their phone lying around. Hiding emails. Saying they are one place then forgeting and saying it was another. I think if she is asking your opinion, then she may be feeling it could have happened. She just doesn't want to admit it toherself. And for him to even say it's cause of her weight, well even though he later said that wasn't the case, that is cruel nasty and spiteful thing to say and being a size 12 myself (going from an 18) I'd have kicked his butt out just for saying that.