Oh wow...
Ok, ignoring the somewhat off-topic parts, unfriendliness, trolling attempts and seemingly deliberate misunderstandings.
The "Sexism in RPG" is not about boobs or other more or less visible body parts. Neither the always almost naked barbarian nor the heroine constantly in various states of undress makes any logical sense in RPGs unless we explain it with weaki stuff like "her clothes are magic, they don't work if she wears pants" because no one in their sane mind would create an item like that. Ever. But really, even if they would and if women (or men) would use such un-clothing in my games...
This is an example I have seen.
Player 1 is an experienced player who wants to play a sexy heroine, which is nonetheless a no-nonsense woman despite chainmail bikini-like clothes and overexpressed female attributes. This heroine likes teasing the males and play off on her looks - as a lot of RL women would if they'd look like that. Now player 2's hero compliments her on her looks, is impressed as she expects and maybe he plays on his own muscles to make her like him. Player 3's hero would make sexist in-game comments, maybe because the char in question can't hold up to the heroine, or he's jealous of the attention player 2's char gets. I'd be all fine with this because it is in-game and sexist people will probably always exist. The other PCs don't care.
Payer 1 who plays the female char is male, nothing much more but the occasional comment about him doing a good job and being a woman and probably a few saucy jokes happen. A few games later, player 1 is female, you suddenly face out-game comments about her playing a stereotype sexy gal and how she would even know how to as she is rather the opposite body shape. And suggestions that she's just playing out her secret fantasies. Plus suggestions - out of earshot of player 1 but not mine - that she may be a tease in RL.
Pardon me? The guy who played the heroine the first time was not only much fatter, he didn't even have the same gender. THAT is sexist (and stupid to boot) - one of the few times we had a real problem in a group because of comments like that. The same group had absolutely no issue with the same female player portraying a fat, drug addicted, lazy elf in a Shadow Run game a few months earlier...
So all in all this does not look like a big deal for a lot of people I'm sure. But it is probably even worse than some very obvious instances. There are quite some examples of things like this going on in the world, including in RPG sessions, they seem so subtle and over all harmless. But those do the most harm in my view because people, mostly the male population, sees such comments and behaviours as normal when in reality it's more or less veiled sexism.
There was never much sexism in any games I played at (I'm not counting not allowing crossgender here) but there was usually a little. In both directions, but directed at female players more often. And a lot of times the people doing it did not really notice, and some times players felt uncomfortable and didn't dare to say anything because it was all "in good fun."