I read it that way as well, but honestly it is often times hard to read people and determine what they want.It's the way it read to me, anyway.
I did not take the man's actions in ripping off the briefs as being a nefarious action per se, it just might have been more surprising than what @SCRob95060 was really expecting. But you get that sometimes. The past experience you just had leading to doing this or that the next time thinking the person wants aggressiveness, and that person was actually not expecting it at all.
It is tough to get all the non-verbal clues right sometimes, but at least SCRob95060 got sexual relief.