Older Spike

Especially fanart and the canon version of older Spike like holy shit

But if you say Spike doesnt count despite being raised like a Pony I would say Sombra. 

Hes such a dominant presence I kind of want to see him groan and devolve in arousal and/or try to hide his embarrassment as he lets me top him. I seem to like characters that are dominant and should obviously be tops on the bottom (like Bowser for example)