From MC’s viewpoint; uncle’s (the one that adopted glasses cousin) ex-“wife”’s baby, he (Omega) ended up marrying a Beta and had a baby through a sperm donour.
Daughter of L ee Chowon was previously married to Park Dojun, Park Dojin's older brother. The super pretty omega
That beta was Hyesungs best friend, so I think that a more realistic POV for Byul would be: "Mom's best friend's daughter" since a child is significantly more likely to know about their parents close friends than their uncles ex-husband whom uncle got divorced from before they were even born.
OHHH I REMEMBER NOWW thankssss
Whose yoobin