i thought the same thing hehehe
OMG WAITTT YES
mhmm..sure, but if you remember back in the last season, Rosa's mom doesn't even seem to like Jaeon. She even told Rosa to be more selective with the guys she's sleeping with, and she made an off hand comment about Jaeon's mom.
Regardless, even if Jaeon sleeps with the mom as an act of "revenge", I really don't think Rosa would even care. She doesn't really seem to care much about Jaeon, and at this point, Rosa is too far deep with Yeonwoo to even care what her ex - sex buddy is doing.
MANNNN THE TIMING OF JAE-EON saying the line "nothing's hitting...nothing does" then Suryeon's appearance mmhmmm I like this since the story's a mess already I'd like the best boi that is Jae-eon get's his revenge too (▰˘◡˘▰) and what better way to do it by sleeping with her mom..I mean Jae-eon already said it before that if he knew Suryeon fw guys younger than her then he would've grabbed the chance.