Did you find out the manga through youtube? I remember recently watching a review of the manga that fits your description. Anyways, the youtube algorithm sure works in mysterious ways...
Yes, that's exactly how I found out about it. All these people, being shocked and appalled, warning society about it's imminent danger that will surely come from a cute manga of a boy who loves his mom, you're only helping me find it.
It's a pretty lovely story filled with drama. I really enjoy age gap stories~