Not sure why some people get so worried about harem shows.
First thing first, it's fictional characters we are talking about. Nothing of this is going to affect your (probably non-existing) personal relationships.
Beside that, this stuff is always as harmless as it gets in the end.
Asexual adolescent main characters rarely ever kiss or "hold hands" at the peak of their hormonal activity, let alone getting their dicks wet.
Not to mention this is a comedy series. Everything being absurdly stupid is precisely the whole point, especially coming from the author of Aho Girl.