He has a point, it's a cultural thing. Japanese men have a thing for women crying and being uncomfortable and in pain (or pretending to be) during sex, for some reason. When you fuck your gf, does she usually moan, scream, grunt or pant in pleasure? Omg, it's almost as if porn was tailored to provoke a sexual response by evoking stuff people find sexually pleasing. This happens to differ from culture to culture.