They do, he probs recognized him but probably confused on why he would visit him (if we look back on the first few chapters you can see they argue a lot or yeah if you get what I mean)
He recognizes Gyuha, that's why he asked why he was there vs saying "who are you?" lol Chayoung moved to the states right before high school, and moved back to Korea like a year before s1 started.
I think that he cant remember them being married with kids, no plot holes just tiresome repetitive trope "amnesia".
oh okay thanks guys
i thought they knew each other as kids…? did i make that up? if he has his memories from 28 and below wouldnt he still recognize gyuha? bruhh i think i’m trippin lmao