I guess I’m the only one who’s going to agree or rather, say that YES. Characters cheating on each other makes a book interesting for me, now that I have it aside let’s make more sense here. Shall we?
In these days cheating is as common as global warming, every other couple has done this. It is REAL, there’s barely a chance that you’ll stay in love with one person all your life. Same goes to the character, falling out of love is easier than falling in love.
Now what spoils it? Characters coming to each other without any conflict, emotional trauma, and discussion. This is where the actual, real trope goes wrong. Getting back with the person who basically chose someone else over you damns you emotionally, the self esteem flies out of the window.
I don’t understand how people can even make the cheaters get accepted so easily, with barely zero efforts from their end. Just like @laura945 said, it needs to be written in a way that it makes sense.