Just found out BF has been looking for NSA meetings?

My BF and I have been together for 8 months and this past week moved in with each other. Two days ago, I found out he has profiles on affair sites and has been posting/responding to NSA ads on CL- including sending his picture out. I have confronted him about this, and of course he said that he never actually went through with any of them. I don't know what to do. I am heartbroken and need advice.