Githyanki lay eggs - they don't give birth live like most mammals. Which means Githyanki have a Cloaca. A Cloaca is an orifice which is used by a bird or lizard for defecation, sex and egg laying.
So I'd pass on that Githyanki sex...lol...ewwwwwwwwww
They also have tits, so maybe it isn't so straightforward.
This reminds me of all the conversations I had in grade school about what possible biological niches Pokemon could occupy exactly.
Or maybe Lae'zel is the world's sexiest platypus
Good point, so they lay eggs but breastfeed their young when born. How confusing. Although I don't get why a Githyanki would want to mate with any other species. Totally incompatible.
If you try to initiate sex and you start taking off your clothes, La'zael should look down and go "Kinchaw, what in the hells is that?" Then "You do not appear to have the correct equipment for this."
Anyway, I think Larian has - based on implementation - decided that sex is largely irrelevant. Anybody can bang anybody. I don't blame them really. It's not the focus of the game for me, and I don't consider cartoon-sex some kind of game-breaking war-crime.