He just called me a b*tch...because HE lied?

I've been with my bf for almost a year now. Ever since we started living together, we fight/argue more and more. And a lot of it has to do with his lying. He lies about p*rn, pictures he saves, and it's not just that, he lies about other things, because I always catch him. Well I saw in his phone when he was holding it that he has this application called "photo safe" where you can hide pics from any viewer of their phone except him & there's a pword & everything. Like I said, I've caught him having photos of naked chics, that he says his guy friend sends him. Which I don't know if he knows these girls or not. Anyway, I casually brought it up asking if he had that app, and he said no. He straight up lied to me! I told him that I saw it on his phone while he was on it & then he said geez shut up you b*tch! I am beyond angry right now & I don't know how to handle this..