Bf ex

So I get a text saying we need to talk... I'm like okay, well he said you know how I was at the bar sat night( he was wth his guy friends at the bar) and I said yes, he's like my ex was there( the one before me) and he told me he left cause he didn't want to deal with drama and as he was leaving she followed him out to his truck and before he got in, she pulled him and kissed him.... He said he pushed away and left but I don't know what to say to him, I'm heartbroken more then anything for it happening... I fall real hard and I love very much... He means the work to me but he dosnt Get it that I'm upset... And I don't know what to say to him he's trying to say I only care about but the fact that it happened still gets to me... He says it wasn't his fault but I feel somewhat cheated on.... What should I do, how should I handle it...