First, while the Realm has no inherent sexism and treats sexuality as matter-of-fact, it also still treats certain types of sex acts as worthy of condemnation. This is why House Cynis has a reputation for debauchery and spending magical materials as marital aids is considered wasteful. Nobody in the Realm is going to bat an eye if your Dragonblooded Princeling has a dozen boytoys on the side; however if he fails to perform his duty to the Realm in propagating the bloodline, he’s going to get a lot of familial and cultural pressure applied to him. So accusations of being promiscuous won’t be curses, but accusations of being celibate will be (unless you are a monk); as will accusations of being impotent and excessively masturbatory. Calling a Dragonblooded impotent or barren will probably start a blood feud, and being accused of excessively wasteful sexuality will result in social censure to a certain degree (which is why what happens at Cynis parties stay at Cynis parties). As mentioned, bestiality is going to be really looked down on, especially because it is associated with Lunar Anathema.
Second; the Realm is remarkably egalitarian about sex, but a lot of Creation is not. The West and the South both have Issues with sex, while still being fairly transgender friendly. Though much like racial slurs, this is the kind of thing that you shouldn’t bring up at your table unless everyone is okay with it.