This time his tears aren't fake, but are definitely out of selfishness(he's crying because he feel sorry for himself) and i agree that he doesn't realistically deserve any forgiveness. However, this is a dark story, so this trope is to be expected. And he will surprisingly change (he still doesn't deserve forgiveness of course, he's a damn rapist) but it will be because he doesn't want to lose mc, not because he'll have character development (he will always lack empathy and compassion, that's how he's wired). He'll just behave 'smarter' since he'll realize that violence will drive mc away. This i guess is more realistic than him suddenly turning into a saint. As for mc, he has extremely low self esteem and is a people-pleaser.
Bottom still delusional asf. He even forgives this asshole of a top just because he sheds some crocodile tears. Ughhhh I hate this plot, this story. It doesn't serve any justice to the bottom.