Sorry My Kid's Bothering You.

Overview

Hiroki, a single parent, is having a little trouble with his next-door neighbor. Hiroki's a very serious businessman and has absolutely nothing in common with the younger, flashy Shohei... Except Hiroki's son, Hideki, starts going to Shohei's apartment and causing trouble. Shohei criticizes Hiroki's parenting skills and even calls him sexually frustrated, so Hiroki forgets to apologize and the two get into a fight. They end up accidentally kissing, and their relationship starts heading in a new direction... (Source: Renta!)

Source: AniList