Errr ... if it turns your partner on, it is. It's called foreplay.
And, no, you don't have to do anything during sex that makes you uncomfortable or turns you off. For Kurose, there aren't too many options since, although everything makes Shirotani uncomfortable, it also seems to turn him on.
Lol, I know, but I just meant that when he told Shirotani "that's not how you talk dirty" and said those things, I just thought he went a little overboard with it. XD
Shiro-tan is still inexprienced with sex- Kurose needs to handle him with care before he can even do such hardcore verbal foreplay!! (๑•ㅂ•)و✧
Not everyone has to talk dirty like you during "that" (I say "that" 'cause it's not exactly sex) ╮(￣▽￣)╭