owl.goes.hoot's activites

So like is anybody familiar with an omegaverse story where the relationship of a pair is falling apart and the omega is actually in pain everytime his pair sleeps with other people like he actually feels and knows it whenever his pair is being unfaithful??? Idk y i suddenly remembered that but pls help me find it. I cant remember the title nor the author ㅠㅠ i cant even remember if it's a oneshot or a story inserted somewhere in a manga pls help

When seme (or male lead if it's shoujo/josei manga) regretting all the bad thing he has done (especially to his significant other) and trying to make amend of his wrongdoings. Some of the list has uke that is very forgiving, never forgive or died. I don't mind whichever ending, it's just the feeling of regret, from doing bad things or taking things for granted. 

Most in the list are yaoi/shounen-ai genre, that's why I used term 'seme'. Feel free to add if you have anything similar in mind.

Based on a famous essay by a Japanese gay activist, this manga tells the story of his life leading f...