Many moons ago The Joy of Sex suggested "Never refuse to try something your partner really likes, & never force your partner to do anything (s)he really doesn't like"...with the understanding that both have to be two-way streets. If he's crossing boundaries that you're not ready to cross, you have to tell him, & he doesn't accept that it's freaking you out as a good enough reason, then the really hard conversation has to take place.

__________________
Plug me into somethin'

If the theory does not conform to the facts, then the facts must be discarded.

No good deed ever goes unpunished

Never argue with an idiot. He'll drag you down to his level, & beat you with experience.