I was binge reading and
Is it about artistic sense? Yes, but it is also very much about him having inferiority complex and insecurity. Artistic sense and whatnot is just the surface issue of his.
Second, he did want to avoid the ex. He just didn't because he saw uke held his painting as precious, something he himself never thought someone would ever want and as we see in the earlier chapters, by extension, him. At that point, he felt someone wanted to connect with him for who he is thoroughly. That is why he entertains the ex, because 1. He saw uke wanting the painting back so much that was the only thing he said he wanted back from his previous house and is also the only thing that uke showed an interest in (he didnt have hobbies or likes as it was. 2. Because he feels it is important to uke, he himself feels important to him. You can see at some point him going a bit blank when uke says he "doesn't need the picture anymore". When you take into consideration media literacy and that usually you saying something means more that the literal sense in stories, what is implied is that seme heard it as him not needing something he always wanted to be needed by someone else and him himself.
Other than these times when seme wanted something from ex because he wanted to help the uke, the ex always was the one to invade his space. He also probably doesn't think much about going to him and putting himself at risk to bring back smth important to uke because, as we can see, he is deluding himself into thinking he is not actually important to uke, even if he wishes to feel that way.
In any case, it is much more complex than uke meeting up with ex "just because". Would it be better if he never got even slightly close to the ex? Ofc. Would I ever do what he did? Heck no, my legs would be running faster than my brain could process. But also, it is not that simple for him, in his head, and it is interesting to stop and think about "why did he do that" and "what is his psyche in it all to every detail"
Seme meetig up*
Also, smth interesting to think about is that as idiotic as it may be, seme probably thought ex would just put HIM in danger, not uke, which ex was already kinda doing, since he was back into the school and seme was always on his wit's end. Probably knew ex would come back for him. While he did pat ex down to see if he had smth on him, he probably thought to be safe just at that moment and didnt think both would contact each other later on, specially considering uke said he "didnt need painting anymore". But also, many ppl tend to have tunnel vision when facing someone like that and we can only think about other things that could happen because we are a third party, so there's also that
last chapter the ex says to seme that he's going to let him go but he's obviously lying lol he even says the he'll always love him I HOPE it's real bc i'm sure seme would keep him around with no problem if that wasn't the case. also if this crazy ex plot drags for another season then it's bc author REALLY doesn't know how to write and it's already bad seeing how it is now. i hope we can finally focus on uke's trauma and his past bc we don't know anything besides that he has a weird father
now i hate that seme's only problem IN LIFE is that he wants to find his artistic identity. that's his only issue and whole plot besides the ex, i think it's interesting and not something we see in manhwas but i can't feel bad for him and get immersed bc wdym the only thing that evokes a difficulty for u is that everyone prefers your mother's paintings BE SERIOUS KFGKD why are u avoiding ur mom for something she can't control and not ur ex who stabbed you?? i don't like him because i hate rich kids who are so immature lol if we get time skip i hope uke gets dicked down by other guys who are as obsessed as him. this read was a ragebait i need seme to suffer or be jealous SOMETHING GIVE ME SOMETHING even i could treat uke so much better i wouldn't hang out with my ex and that's the bare minimum