Astarion trying to get into your pants at every opportunity seems pretty on brand for a vampire tbh, lore wise they're pretty damn horny undead in any given iteration of their lore if its dracula that has to seduce/hypnotize virgins (oh suuuure it's because of their 'pure blood' w/e drac was hornt af) or astarion trying to get into your pants whenever he can after
you feed him some blood.
lae'zel's horniness is weird but can become on brand if larian develops her fascination for fae'run and let the MC cultivate her curiosity, gith don't seem to really be the type to be overtly into romance and would probably be more into the carnal lust if anything so this can still be on brand here, if developing enough approval she does start to develop curiosity about fae'run and its inhabitants as she's still a complete stranger to these lands which I dunno, there's some good potential there.
shadowheart's fine really imo
gale/wyll not explored yet will do in other playthroughs if I can't get find workarounds for some gamebreaking cyberpunk bugs
but gale seems like he's a horny karsus where as opposed to wanting to become the god of magic himself by killing & replacing mystra my boy gale seems to go the route of becoming mystra's husband, his connection to netheresse magic as well make me think he's more of a horny karsus atm
loading screen is already super hornt and he seems to have a lady he's chasing after so not sure how good being a homewrecker would feel there lol