Displaced broken woman: new place, environment, etc.. just out of a bad relationship.
New place = new guy. And he's also vulnerable- some kind of heartbreak... but he's a good man. Not the cliche "nice guy".. but an actual good man- responsible, honest, hardworking, etc.
They meet, he's gruff and abrasive, so she doesn't like his rough exterior. But then she finds out his vulnerability. Whether he lets it slip or one of his friends tells her, or she's just super observant, she finds out... and softens toward him.
Then they get their freak on.
But I realized recently: The sex isn't her fantasy- her fantasy is the good man, the man who will respect and protect her. He will treasure her heart.
See, I really think that in these books, the real fantasy, what the readers are really looking for is the dream that there are still good men available. Someone who is intelligent, kind, honest, hardworking, willing to commit, and capable of loving her and treating her the way she wants to be treated.