Please suggest a book for a friend who is in a dysfunctional relationship

So my friend is a very sensitive, sweet, caring guy. One of the kindest people you’ll ever meet, and very emotionally open. His boyfriend is emotionally distant, shows no affection, and can sometimes be outright mean (like insulting my friend’s hobbies and interests). My friend craves affection and is so hurt by the situation. He would like to break up but isn’t quite ready because he badly wants to fix things (though his boyfriend is not putting in the same effort).

I’d love to gift him a book (preferably fiction) that portrays a similar relationship, or even someone breaking up. Not to push him to do anything he’s not ready for, just so that he can feel comforted to see his own situation reflected back at him, or maybe help to understand it better. He’s often saying to me he feels there are so many red flags in his relationship and he doesn’t know what to do, and I just really feel for him.

He’s just going through a tough time and we usually gift each other books during these times!

Any suggestions are appreciated.