dubcon renben is so juicy bcuz like. here's the thing. it's not like what ben wants doesn't matter. it does! a lot! he's a future knight of ren! the ultimate hedons! it's all about taking what you want! and there's no shortcuts allowed, either--ben has to genuinely want it, no 'exchange for something he actually wants' or 'convince him he's supposed to want it' or anything like that. the action isn't enough. ren needs the desire.
...but. there are no rules as to why ben wants it. so: aphrodisiacs, hypnosis, conditioning, maybe even force-mediated brainwashing shit. ren isn't ever going to hurt his boy--oh no, far from it--but he has zero qualms about messing with his head if it means their desires align. if there was a control room for ben's brain ren would be in there mashing buttons faster than you could say "this feels like weird snoke shit". and that kinda makes the whole thing fascinating for me, in a way that a lot of dubcon doesn't always manage to hit--like, okay, ben wants to, but does it still count if that desire's been conditioned/hypnotized/implanted in him? is it still consensual or is it taking advantage? or is it somehow both at once, ren taking advantage of the way he's created ben's consent? and does ben even care?