So, I agree here with others. I think we have to do what we are comfortable with. Tell him, "ya no, I'm not saying that. It's not me to talk like that". And if he doesn't like that you won't talk dirty or participate in everything he likes, then you may not be compatible sexually. If you don't care and it is no big deal, then you can appease him. If it legit makes you uncomfortable, tell him no. It's your right.
Remember, intimacy and sex is for YOU too and not just him!
So, have you told him that you don't like the way he talks to you in bed? Cuz if you have, and he continues, i agree that it seems you're sexually incompatible at this time. If it were me, i would exit the relationship and find someone that didn't make me feel uncomfortable sexually.
If your boyfriend doesn't care much about what his girlfriend likes or feels comfortable with, and is fetishistic about the size of his equipment, maybe it's time to re-think the relationship and find someone who is not so self-centered about sex.