Not only is he okay with someone discussing having casual sex with you, and not only is he acting incredulous that someone else is choosing to have sex with you, but he is commenting on your body after being asked not to and he's doing it in a disrespectful way. I would consider distancing from this friend.

I think the way you're phrasing it here is fine. I would go with a simple "So far, I've enjoyed being with you, but in order to continue moving forward, I need X."

Try not to overload him with everything all at once. If you have a list, give him a couple at a time so he doesn't feel attacked.

Good luck!