The fact her CLUB MATES KNEW and not ONLY supported her, but were involved shouldn't surprise me it lasted this long, or that she felt even MORE encouraged to continue it! She found herself surrounded by even MORE "Red Flag Girls" like herself! So no wonder she was so arrogant!
Just like Miyuki from "Jinsei" her motivations in the end was "Spoiled brat REALLY putting the pressure of being a good person on her "BF" expecting to be forgiven and accepted back! MC is lucky he didn't! He only has to
I'd not be shocked that she's an Affair baby and her "father" suspected, but chose NOT TO DO THE TESTS, not wanting to know because he knew if he did, he'd FALTER in forgiving her skank of a mother! So the HORROR that "Like mother, like daughter" might have SHAKEN HIM and made him regret forgiving her, even REVISITING if she really IS HIS now! Guessing the writer didn't want to DIVE that far, but would be an interesting ADDITION to her karma if he DOES DNA test her, but wheatever she is, or isn't is left open, feel it's TOO EASY to think she is a cuck/affair baby, and being her Father's just adds to what i like MORE from her, that in the end, INSPITE of her cheating skank of a mother and genetics, she's a cheater and that was by her OWN CHOICE! No easy way out with that Genetics nonsense! So happy she lost him, doubt dipshit cared too much losing the FL to MC other then the dude he was cucking for years took his "Babe from him" as you know the Alpha male fucks like him got off MORE from the STEALING another guy's girl, her being a childhood friend turned girlfriend made her likely more appealing
Hope she IS stuck with the fucktard, we know that will be the DEATH of their chemistry, since in the end, their relationship amounted to "Cheating, cheating, cheating, the thrill of getting away with it and almost getting found out" and nothing more then that! A relationship was never in the cards, especially with Fuckboi, he was NEVER giving up his freedom for NO ONE! She's a FOOL for thinking he'd even TAKE responsibility, especially since cumming inside for him was just taking the ULTIMATE WIN OVER MC since he wasn't satisfied with just fucking her and stealing her first time. Know he had to make her COMPLETELY HIS so that no matter what, he likes to think MC will feel something wrong, but never figure it out why or whatever! They are mental after all!