I guess at this point I would suggest that you not mention it again. He clearly does not want to acknowledge it properly--and neither of you really knows what would be proper.
I would wait and see if he suggests anything that sounds remotely like fun. Your backup plan should be to go out for dinner and then karaoke (or something). If he suggests hanging out at home and getting "fired up" then you can tell him your plans and tell him he is welcome to come along.
If you end up going out alone, stay out late, and I would suggest being "tired" when you get home.
