Well, it hasn't happened yet through the end of volume 2. And it's not really that kind of harem series. It actually takes things pretty seriously and realistically. Even the sexual stuff that occasionally comes up tends to be handled in a serious and mature fashion instead of used as an excuse to show sex appeal.
Even if events like that do come up, it's really hard to imagine them being used solely to show off some sex appeal thing. Every example of overtly sexualized imagery so far (again, speaking as far as the end of volume 2) have always had proper plot/setting/character development reasons behind them. And even those are fairly rare and usually extremely tame.