SOOOO, the key here guys is actually for the two of them to really COMMUNICATE.... For Hyesung to stop Dojin for what he is doing every time he gets mad or jealous and to show him some love and his true feelings. For Dojin to actually respect his partner and stop showing his aggression by sex and treating her uke right. HONESTLY, THESE TWO NEED BONDING TIME NOT IN THE FORM OF SEX.
You're allowed to be bothered when you see your partner (which is 10 years younger than you are and has absolutely no love experience because you forced him to stay by your side) finding other people attractive, and this is why communication exists. All Dojin knows is forcing his way onto Hyesung to make him agree on whatever HE wants to do. And it's been like this since day 1. Just because he was jealous doesn't mean he had to act like a whole ass possessive boyfriend and totally force him to have sex.
Like I said tho, i'm not siding Dojin here, if you read my reply too, both people here have problems, they don't communicate, both of them are beginners in establishing a relationship. And Hyesung was not forced to stay by his side, he got away from Dojin before. He even agreed to marry him. You might see it because they were bonded only and because of Byul, but it was still his choice. I said there that Dojin really needs to respect his partner, and learn how to treat his uke. And Hyesung also needs to put his stand and discuss it with Dojin how he disliked being forced to sex whenever he gets jealous. They should learn how to show affection not in the form of sex.

I don't know if you guys know any other manga that talks about a partner/lover watching porn or ogling another celebrity/personality, same with having to meet the ideal guy/girl where the other partner got jealous/insecure of it. But I think some relationship, whether they are just dating or already married with kids experienced this once or twice in their life. Should you guys expect the person not to get bothered by it, if your partner on the other hand appears to be cold/snobbish to you and shows a bashful cute face while seeing an attractive and sexy person?
It might be petty for some, or they might not be bothered by it because they don't experience it firsthand, but it still does happen to other people in a relationship. I'm not siding any character at this point, not Hyesung or Dojin. But look at it this way, they started with a purely physical relationship, and didn't even tried to know each other first nor do they date like other couples do. Hyesung got preggy without him realizing his feelings and have a lot of baggage from past experiences, also in denial of him being an omega instead was aspiring to be an alpha. Same thing with Dojin, he did not care for anyone other than himself, hated omegas because of his past experiences, and never had a serious relationship or dated someone he really loved because he is an alpha and they just chase him for his status, with or without love. He is not used to someone like Hyesung, who doesn't shower him such love or appreciation, (doesn't care about his alpha status or put him on a pedestal) so he gets really childish and acts possessive.
Guys you have to understand that these couple won't just suddenly change their personailty just because they got out of an obstacle before and realized their own feelings, even when they are already married. They are beginners in love and establishing a relationship. They haven't even have a proper date without having any trouble. They don't communicate properly because how they show their love is different. Dojin is very physical, he lacks romance. Hyesung is very tsundere (cat-like) so he doesn't show by words or actions. He is very prideful too, I mean both of them are.