@angrybrony
Also, do they even have a way of expressing or deriving physical pleasure? Can they be or have they shown to be turned on?
The closest I can think of is Blackarachnia and Silverbolt from Beast Wars. Yet as far as I remember that was more belligerent sexual tension and a bunch of flirting, mostly from Blackarachnia with Silverbolt acting more like an knight who kept being nice buy trying to convince her that she didn’t have to be with the deceptions.