if she needs to be convinced then she is probably already pretty stupid and should be ditched at the first opportunity.
There is no actual way to prove this. You just have to try and convince her by being nice and romantic and not cheating. Apart from that all you can do is hope for forgiveness.
Try, I don't know, NOT CHEATING.
If you have a girlfriend and a boyfriend, then you are cheating on both of them.
maybe, maybe not.If he spends more time with the girl he is cheating on.
You can tell for sure that your girlfriend is cheating, by catching her on the act with her lover.
he is totally cheating.
I don't dream about your girlfriend
then he must be cheating on you if he has a girlfriend? i mean if he likes you and has a gf then he must be cheating and wanting you?
Follow her
yes, it is
stalk her
no