I think you both are missing the point. Everything Seiei and Saku knows about gay sex they got from mangas. So when they were referring to how a top or bottom should act it's more than likely because they are basing it ON THE MANGAS that INFLUENCED them. They're LITERALLY BOTH VIRGIN young boys who have no experience or knows what's normal or not. It was a running gag and y'all missed it.
No i didn't miss it, all i pointed out is that he sounded like one because he did. Like that's kind of the whole gag? plus even if it was a running gag people are allowed to find it unfunny since atp it gets annoying and repetitive since literally that is all they talk about. When it comes to comedy making the same joke over and over doesn't always work, plus the manga includes an adult dating someone barely legal (some people find it okay but I find it morally wrong due to the huge concerning maturity difference) so it's quite hard to find the point of the story when they include something like that. You can find it funny but this clearly didn't fit our demographic.
You can tell this is written by a inexperienced straight woman that has no idea how a gay relationship works. There is no certain way you have to act or look to be a bottom. You either like being fucked in the ass or you don't.