My only problem with that side ship is it seems that the think that made them have an epiphany is that Sugita got a big dick. Not that there's a problem with like things like that, sure, but it seems that Ruka is more motivated by his body and not by him. I'm a "mind over mater" kind of guy when it's come to shipping, so, it's irking me quite a bit. And, yeah, Sugita was nothing but tired of Ruka's shit until this chapter, so, it's coming a little bit out of the blue for him to go like "yeah actually I like her more than I tought". We should have more Sugita centric chapter before going to that point.
I dunno, I don't think the ship is horrible, or coming out of nowhere (it's quite previsible actually), but I think we need more chapters about the two showing that they don't have such a bad relationship and that they actually care a lot about each other, and not the "jealousy epiphany" bullshit. (not that the trope is bad, tropes are tools, but it's way overused, and here, it's really not the best way to use it)