Most of the time you just feel it. You notice your mate is not as affectionate as they used to be. Or they are overly affectionate because they feel guilty. ITs always the little things that give this away. Secretive phone calls or emails. Stuff like this. I could make a really long list. But the basic thing is if you feel they are cheating they probably are.
He isn't cheating on her.
you will know if your cheating when you are dating someone and dating someone else at the same time.
Justin Bieber is not cheating on her.
Try, I don't know, NOT CHEATING.
The Patriots did not cheat. Therefore they could not have known they were "cheating".
If they know about each other then no, it's not technically cheating.
Ask her if shes cheating on you! Nah im kidding i dont know sorry ? :( and im a guy
Most likely in the same ways that you might know she was cheating with a man. It could even be less obvious, though, especially if she was cheating with one of her female friends.
atitude
ask him
Follow her
Ask her.