I wanna say Siwon probably thinks he isn't deserving of love that's why he doesn't trust that Woojoon could actually fall in love with the real him so maybe he's gonna try to be such a menace to test that theory. It also doesn't help that the mc claims he's his fan but didn't remember that Siwon's parents are gone and he's been injured this whole time, cuz he kept mentioning share this cake with your parents and all that.
I wanna say Siwon probably thinks he isn't deserving of love that's why he doesn't trust that Woojoon could actually fall in love with the real him so maybe he's gonna try to be such a menace to test that theory. It also doesn't help that the mc claims he's his fan but didn't remember that Siwon's parents are gone and he's been injured this whole time, cuz he kept mentioning share this cake with your parents and all that.