Oh, that's a fascinating one because it forces a transition from competitive tension to physical intimacy. Their rivalry is so grounded in volleyball—their whole dynamic is built on pushing each other to be better, that almost aggressive admiration. So a story that shifts that into a sexual context has to find a way to translate that push-pull, that one-upmanship, into a new arena.
I've seen some that do it well by keeping that competitive edge. It's not just sweet romance; it's about who gives in first, who's more flustered, that same fiery energy redirected. The best ones I've read make the physical act another form of communication for them, as intense and wordless as their quick attack. It can feel like a natural, if explosive, extension of how they already are.
Though honestly, sometimes it just feels off. If the writing leans too hard into dominant/submissive tropes without that underlying mutual respect, it loses what makes their dynamic special. It has to still feel like them, you know? All that pent-up frustration from the court finding another outlet.