Rita just mocking Asumi when she clearly told her to stop multiple times kinda put me off the sex scene tho.
Asumi never "clearly told her to stop." She did say things like, "Wait" or "go slower," but she never insisted on anything.
This was standard top-bottom sex patter, not a rape scene.
Adding to this, I don't remember under which series it was, but i remember ppl talking about how it's kind of an engrained thing in Japan to say stuff like Wait, not there, etc. due to purity/restraint/whatever it was called stuff.
Def weird to us Westerners but not the same as refusal or even disapproval on Asumi's part.
So that, in addition with how Asumi has the whole bottom shtick of liking to be "bullied" a bit, p solidly indicates that she's actually against anything Rita does