How do I tell my girlfriend that we need to break up?

Whatever you do don't break up over the phone, IMs or text just take her out and tell her that things are going well and you want to break up. Oh yeah don't take her to the place were you first went out to eat hope that helps if it not 2 late yet lmao.

You want to end it off of assumption? You're not even sure and your already calling it quits. You must not really want to b with her over something so small and unsure about. So, maybe you should because you obviously aren't that really into her. Otherwise you'd not b thinking about leaving her. If your gonna end it, just tell her.

If you really have strong feelings, I really believe that you should not be doubting one another. Just because she doubts you, does not mean you should doubt her.

Back on topic, you just walk up to her and tell her straight: "this relationship is not working out, since neither of us are able to trust one another. "

If you have any interest in keeping things going, ask her why she is always asking you if you are cheating. Your next move depends on her response.

If you just want to break up now tell her that the cheating inquisition has poisoned the relationship and something is obviously wrong and that you think you should end it. Of course, if you've cheated with another girl in the past you at least know why. And you've made your bed and now you have to lie in it. Literally. Your bad.

Dude, just tell her (not over the phone--that's for pussies), Meet up with her and just break the news, it's not that serious to where you have to contemplate over how to tell her, it's not like you guys are going to get married. Just make sure you really want to break up with her before you do so.