Me who is reading the raws but cant understand a thing: What the hell is going on???

The top still has lingering feelings for the uke and if i understand correctly the top has a problem with something called mark? (Not sure tho) and they want the mc to help the top

Idk maybe in the past 7 years the top was marked by another omega? And seein by the MC's reaction he seems happy and satisfied that the top is suffering (idk if my understanding is correct or not)