well the whole premise of the story at the start is kind of that seonwoo (brown haired lead) is in love with jungho (groom in ch1) but junghos straight so its not really a 2nd male lead i wouldnt say? theres some moments where seonwoo has stuff with other people ig but those are more random bg chars rather than a whole plot.
for SA i'd say kind of. theres no rape, but yuri is a bit... forceful at times. i wouldnt say its too bad other than one specific chapter (but like idk id say its plot relevant and not fetishizy). if you're sensitive to topics like that id be cautious but its a worthy read imo. theres a lot of emotional instability from everyone basically #-.-)

before i get into reading, is there SA or 2nd male lead? or anything of the sort?