The guy isn't dating the bully, he's dating another girl from the club (the one in the flashback on pages 40-41).
I have no clue why he would be hanging out with the bully girls, though.
Or maybe none of these girls mea anything to him and it’s just amusing to watch? In this world guys go through women like toilet paper if they want to, so all these girls are disposable.
Ah, someone who knows the true meaning of alpha and beta.
Masato is a true Alpha, but he has yet to see that he can take his place as a lover to the Women doting on him.
(Not the loli, she can get told to wait patiently, she's too young)