This one's kinda obvious because he was a cheating bastard, but the fact that the uke still wanted him (/TДT)/
http://www.mangago.zone/read-manga/overdose/
Yup! There were some Yaoi mangas were I didn't like the seme but I forgot the names to them, one of them was the seme was a big player for girls and even tho he kissed and had sex with the uke he still has sex with girls and at the end he had sex with some girl and it just ended there and I hated that manga because the seme was an asshole and a damn cheater! >:(
Yes, omg here.
All of the semes in this are horrible. (/TДT)/
I am only reading it in hopes that the uke will grow some sense and learn how to escape without announcing himself. (╯°Д °)╯╧╧
http://www.mangago.zone/read-manga/hogu_hagyeongsu/
Have you read a yaoi manga with a seme MC that you REALLY hated? And I mean full on, I-would-totally-kill-him-in-real-life hated? A seme so unlikable that you honestly wondered why the uke was even willing to be in the same room as him, let alone date him?