Hello! I understand that you are upset but I will try to give the bf perspective (even though I’m a girl! I would so something like this)

He is probably a bit immature or just a silly person. Maybe he whips it out because he is used to do it with his friend? Or because he thinks it is funny. He is probably content with his penis and that’s very good. So you saying “no it’s weird” might do the opposite of what you are trying.

Instead maybe Try to sit him down and say you love his dick, but because of the SA you don’t feel comfortable just being “surprised like this” and then again say you love him and his Dick for who he is ;)

Good luck! Wish you all the best’

My boyfriend does this too as well and presses it against my face. We laugh and we both think it is funny. And I can do the same way with my boobs or other weird things.

He is very comfortable about you, and it shows. Enjoy your relationship! ;)