In my opinion, if your boyfriend cheats on you, and lies about it, you should leave him. This might not be easy as it is said but put in mind that if he did it once, he can always do it again. Hook yourself up around friends and meet new people to deal with the break up.
Wow is this a serious question wheres your brain FIND A NEW BOYFRIEND END YOUR RELATIONSHIP BEFORE IT ENDS YOU he cheated he lied he broke your trust & you still call him your boyfriend seriously I know so many gorgeous girls that get treated the same way there's nice guys out there ready to treat a female like a queen & your wasting your time on this boy
I think I get why you just need to hear other people's thoughts on the subject. Here is my opinion. If you know for certain that he has cheated and lied to you about it then he needs to be an ex boyfriend. Break up and move on. It's hard to do and some just can't make that choice. I hope that what ever you decide makes you happy in the end. You can't be happy staying with someone that you can't trust. Think about it.