I think Siwoo felt like Byul was not being entirely serious about liking him back, so Siwo...

I think Siwoo felt like Byul was not being entirely serious about liking him back, so Siwoo made it aware that he’s an alpha and not an omega. I don’t think this was with the intent to assault Byul but to give Byul a “wake up call” bc he doesn’t want to be another one of Byul’s 2 week relationship then break up