Not that I'm objecting, but it's kinda weird that they're so brazen in their perversions, but have not confessed to each other yet. I mean, it's no longer a matter of his being tsundere, or of there being any doubts that they're attracted to each other. If there are no misunderstandings or mixed signals, the only reason to not make a move would be shyness, but can we really say either of them is shy with all that sexual tension going on?
Another possibility would be something like "s/he's only physically/sexually interested in me", but there are too many instances of each showing affection beyond the physical at this point, so that explanation would fall flat if it were used.
So I hope there's no misunderstandings arc coming, because at this point there's nothing left to misunderstand.
It's been a solid progression from recognising the physical attraction in isolation (which was the point of the initial fetishisation), to recognising that the attraction is mutual, to recognising that the
way they're attracted to each other is actually okay (in particular that Eguchi fetishising Izekawa is actually okay, if he's okay with it and she respects his wishes/concerns), to recognising that they actually like each other a fair bit (even if the sexually charged nature of things makes it difficult for them to separate the emotional attraction from the physical attraction).
A more "normal" couple might start with regular normal social interaction to build the foundations for friendship and confirm individual attraction, then progress to spending some time together around school or even after school to figure out if it's really mutual, and then move on to develop all that into a "proper" romantic relationship. This pair are just crazy fucking weirdos, and got to that last point ("hey, lets go out", "yeah, sounds good") their own unique way.
Except that I think half the point of this manga is probably that this
isn't as weird as it seems - it's exaggerated, sure, and the fetishisation aspect is particularly exaggerated (along with the fact that it's the girl doing the fetishisation, which is a neat way to flip a bunch of stereotypes on their head), but in reality most relationships don't follow that nice neat progression I described. A whole lot of relationships start with something a lot closer to "whoah, they're hot" and "hey, wanna fuck?" than most people are probably comfortable admitting; that happens with kids about this age (16+) among their immediate peers, again a lot more than most people are probably comfortable admitting. Frankly, most of those lovely romantic stories that start with a confession behind the gym or whatever are closer to this model than to the "ideal" - how many of those stories involve almost total strangers, with nothing more than basic physical presentation feeding into the decision of whether or not to say yes?
Anyway, I don't think they're going to be reaching a point where they're even going out normally for a little while yet - there's no need to add further layers of misunderstandings to stretch this out for another ten or twenty chapters.