Confused

I met a guy and we went on a first date which led to sex. Yes, I know it’s wrong and shouldn’t done it. I’m aware but after that he still speaks to me but he’s so dry. It’s like he still initiates the convo but it’s dry. He wasn’t like that the first few days after our date. Should I speak to him about it or should I just let it go and be dry to him also which is something I do and I open his messages Un purposely to see how he feels about me...