the guy i'm seeing is cheating on his gf with me, suggestions?

I really dont think telling her will really help her, but you should confront him.

If he will cheat on her, he will cheat on you and anyone else probably. Tell him he should just be single if he wants to sleep around or have variety. He should let her go if he doesnt want to be exclusive to her.

well the question is how did you find out? if you know her name go on fb and look for a phone number.. if not found send her a message either asking to see her (best option but she may be freaked out) or just plain out tell her in the message. and of course make sure he knows its over

Okay, so you DEFINETLY have to let her know.

I mean, you don't want a guy you've been with for five years cheating on you right?

Even if you let him go and don't tell her, he'll cheat on her with another girl.

He's clearly an *** for doing what he's doing.

Tell her, thats the only best thing you can do in this position:)

I would find some way to tell her, maybe not in person, like facebook or find out her number. And tell him you know, via phone call. AND, dump him! Once a cheater always a cheater.

Stop screwing him and yeah you should tell her I mean wouldn't you want to know, maybe you should save a text from him or have some kinda proof that you guys have been hooking up though just in case he tries to pull the whole "she's lying, she's crazy.." bit..

Are you absolutely sure? If you are, confront him about it, but if you do then all trust with him is broken. If he admit to it or if your absolutely sure, then she had every single right to know. You shouldn't be having sex with someone you don't even know that's like one of the first things you learn about someone. Five years eh? Sounds like he uses her when he doesn't have anyone else. She has every right to know. Why would you unprotected sex with someone!? Thats how babies are created!

Homewrecker!

Well for starters you could quite being such a whore and have enough self respect not to allow yourself to the the other piece when nothing else is avaliable.

Dont get with him because if he cheated on his gf with you he will cheat on you and yes i think you should tell her she has a rigth to knwo

Singing telegram ... its hard to go wrong with one of those.