Honestly I don't fully agree but I do understand what you're talking about I fell pretty similar especially during the side stories when they are in Paris and the uke(joobin) apologizes and says it's his fault. But I don't think the story portrays him as being in the wrong I think the story shows how both of them still need a lot of work in their relationship especially since yikyung(seme) tends to also blame himself a lot and before the uke apologizes and says it's his fault after the seme apologizes and says it's his fault. And you can see this constantly when they have disagreements or problems arise. I think the uke has a bit of people pleasing in him which is why he apologizes all the time which we can see because of the flashback scenes of his dad so he tries to please other people by doing something that he didn't even want to do like photography. And I think the seme tries to have a illusion of control over the situation typically. But I think the reason why it's constantly brought up is because the uke still works in the same profession with the same people in the same group of people he has slept with. Even though a lot of people in the group that he's in know that he's dating someone they still try to get with him. And it tends to cause a lot of problems in their relationship. But especially in the side stories. I really just wished they would stop blaming themselves and find a equal ground that both were responsible with the uke letting the other guy continuously give him drinks and touch him knowing that he's flirting. And the seme for purposely trying to make him jealous by talking with his ex. I think both have faults that weren't fully talked about and I wish it would have expanded more but I just hope it doesn't continue into the new au! (Also this is just my opinion but I really agree with what you said!!)
I agree with your opinion too ,it's just that I found it annoying that the uke has had to apologize and make up for it when he hasn't done anything wrong. I was okay with it in the main story but bringing it up in side story ,I felt was unnecessary considering that we've already been through an arc with the ex . I wished the uke put his foot down coz it's unfair to keep bringing it up especially since the main reason he was sleeping around was coz he wasn't in a good headspace at that time
I agree that slut shaming isn’t right and I liked the way u worded this becuz I agree with you too - but honestly there was a lot of friction imo bout the seme having been less experienced which caused this issue as well.
The seme states multiple times that he’s insecure bout being less experienced to begin with, he properly vocalizes this to the uke and I feel like there’s many instances where the uke doesn’t understand that and instead also takes it like a direct attack to himself (as in he takes it personally even tho no one’s blaming him)
Like of course the seme came in knowing he had a past which didn’t matter - what mattered to him was, as you said, the profession and the people who surrounded him. All of which he slept with at one point or another. Like I think it’s just reasonable he’d be unsure bout it one way or another.
And the Paris fight? 100% was an issue caused by the uke. Cuz why knowing, having previously talked bout it, even tho it’s his job - still be drinking with this guy who’s clearly disrespecting his relationship and then get jealous when the seme not only tried to respect this but also was talking to HIS ex. His ex, who was the one who had more perception than his own boyfriend, and encouraged him to take some action becuz clearly neither of them were.
I feel like a lot of the times he dismisses the seme’s VALID concerns as being less experienced and unsure, yes he tells him it’s not him and he needs to stop apologizing but they never get to the crux of the issue, they just smash for 2-4 chapters.
Honestly I agree I really don't like how they brought it up again and how both the seme and the uke both really showed their insecurities within their relationship and that they still have a lot of work to do on trusting each other and being honest with each other and putting boundaries with each other and with other people. I think one of the reasons that the uke has to apologize and make up for it is because I think he feels like he's done/doing something wrong because the constant problems in the relationship is typically because of his past doing and not telling the seme about it until it actually happens and then they talk about it. I just wish they were more honest with each other especially with how the uke can be really self-destructive at times and blames himself a lot for the problems in their relationship which is why I think it one of the main reasons why he apologizes so much especially since the seme has less experience. Plus I think the uke thinks that his past is too much for the seme especially when the seme tries to take full responsibility over the situation and/or blame himself.(also sorry for the late reply! I didn't expect you to reply but this is just what I got from rereading it!)

Am I the only one who doesn't like that the story keeps lowkey shaming the uke for his past? Not just once or twice but multiple times throughout the story,the uke is made to apologize for sleeping around in the past eventhough there's no reason for him to apologize. Its not like he was having crazy orgies or leading people on,its just that he had a lot of casual relationships and flings. He and seme didn't even know eachother then and the uke cut everything off once they start dating. Yet the uke is repeatedly made to feel like he needs to make up to the seme for it and feels sorry for hurting the seme when he gets jealous about it . It made sense in the beginning since the seme is inexperienced and both were insecure about their relationship but this persists even in the side stories. Granted that the seme never shames him for it and he just gets jealous but it was still annoying that its portrayed as the uke being in the wrong. I don't think I've ever seen a red flag manwhore seme apologize and feel guilty for their past as much as this uke has had to do.