I do wonder if uncle is being intentionally written as aro ace or if it's more the curse of harem manga having to continually up the stakes while not confirming an end game ship until the very end.
The thing is hes super dense because the only thing he ever did was being a gamer otaku nerd with 0 social interactions specially with girls, thankfully it has nothing to do with the sexual orientation yadda-yadda i see in every corner
Edit: yeah theres also the thing he got so backlashed by his appearence he prob thought no girl would ever fall for him, sad