Yeah, I get it, villains are evil and that bleeds into their sex lives as well. But after a point, it's just tacky.
Over on Fanficrants every couple of weeks or so we get a rant pointing out that just because someone is a villain it doesn't make him evil about everything, such as sex. Bad guy X might be evil, but that doesn't mean he'll have his way with the hero/heroine at the first convenient opportunity. So its amusing that so-called professionals fall for the dubious idea of making everyone and his brother a rapist just like bad fanfic writers do.