be as honest and sensitive as possible and make sure that you have proof that the person was cheating
What I would do is tell him that she is cheating and give him some good proof and if he dosent want to believe you then that's his choice. Hey! You warned him!
You can tell for sure that your girlfriend is cheating, by catching her on the act with her lover.
stalk her
Yes you should tell her that he is cheating. Because later, it will hurt her if not told.
One way to try to tell if your girlfriend is cheating is if she's refusing to spend time with you. If she has a new boyfriend she may want to spend less time with you.
you show her who is in charge and put her in her place
you can't. just have to trust her, dude.
tell her.
talk about the person's bad points or have evidential proof that the person is cheating on them such as pictures or videos on youtube.
There is no test to take that will tell you if your girlfriend is cheating on you are not. Girls all act differently and the fact is she is either cheating or not and no test can 100% tell you.
Your girlfriend's cheating