I've dated women that were not comfortable with it, I've dated women that loved it an encouraged it, and even some who enjoyed it with me.
The only legit reason why a woman should have a problem with it is that she would rather you be spending that time with her naked, she would rather enjoy every orgasm that you have with her too.
MOST women do not like it for 1 of 2 reaons
1) they are insecure
2) they feel porn is somehow morally wrong
I try to weed out both types of women when dating. A girl doesn't have to LOVE porn to be with me, but she can't be insecure about human sexuality.