What kind of lie is grounds for breaking up?

my boyfriend and i have be going out for almost 7 months. its been better than any other relationship i've been in. he says he loves me and i'm the only girl he's ever loved. but from before we ever got into a relationship he told me he was a virgin. he has lied to me extensively about it. we have never had or had any plans to for a long time. but today he finally told me he had lied about it in the beginning and he had in fact had with a previous girlfriend.. and then didn't want to tell me cause he didn't want to hurt me and for me to leave him. i don't know what to do. if he lies about this.. i don't know what else he will lie to me about in the future. the trust is gone. i don't know if i should just break up with him now and save me the future heartache... or give him a second chance and try to get our amazing relationship back...