I'm not going to wade into the argument of whether or not rape plots should or should not be allowed on games, or else I'll just argue forever. (FOREVER.)
But God, it just makes me remember this one player I had years ago on a game I staffed on who would clearly, like -- I swear to God, she would seek out sexual assault on plots we were staff-GMing. And it was this weird game of hahahaha no wtf we're not raping you on a plot. No. Go away. (She was a problematic player all around, this was just one wtf facet. She was just very focused on victimizing her character as much as possible in a way that made others super uncomfortable. Most of the time that was just her choice, but we didn't certainly didn't need to enable it through the staff plots.)
If discussion about actual sexual themes is still open -- I've mostly staffed games where the general attitude was "Sure, if you want, just put a warning/notice on the log in case people don't wanna read your TS." I believe pretty strongly that you can absolutely have character development -- even major development -- and real story through sex. (On one game where posting TS didn't seem to be the habit, a friend and I refrained from posting several logs of ours and were actually sad about it just because there was like this major arc in the characters' relationship, it just happened to be intertwined with a part of their sexual relationship. But best to respect game culture, so we kept our sexytimes off the logs page.)