you are aware of the concept of switching, aren't you?
It's not that you have to label him necessarily as a seme or as an uke. Being top or bottom is not a condition in which you are born that remains unchanged for life
He simply changes according to his partner, with siwon he would be the seme and with jinha the uke...
Ah.. so he's like that, huh? With the way he's drawn, he looks more like an uke to me.
In real life, I can see people being like that, but in mangas, I guess I'm just used to characters having one role. Lol.
It's really tough to figure out if Seonyun is a seme or an uke. （￣へ￣）