How do you kno when you boyfriend is cheating on you?

You will never know for sure unless you see it for yourself but he will give off signs that he might be. Such us randomly not being able to see you and not really having a good excuse why. Texting another girl a lot and putting loads of Xs or hearts. Not letting you see his phone cos of he has nothing to hide why wouldn't he let you see? Him starting to see another girl more than you. but all of these or just signs and if someone says he is confront him ad ask and see if he is lying but never go fully on what a friend has said cos they might have got it wrong. You will only know for sure if he is if he tells you himself or you see him kiss another girl etc :) hope this is helpful x