Can a hook up ever be more than just that?

What do you do when someone you see as merely a friend with benefits starts to develop feelings for you? Or better yet you start to develop feelings for them?

Is it possible for a guy to think of a girl he goes to for hook ups as something more? I wonder if guys ever get attached to their "go-to girl". It's a curious matter because women typically like to get physical while involving their emotions. If a girl doesn't feel anything for a guy it's hard to continue hooking up with him out of convenience. Guys on the other hand can separate physical attraction from emotional attraction and will continue to hook up with a girl even if there is not emotional pull.

So is it then possible for a girl to see a "go-to guy" as nothing merely than a hook up? Things would be so much easier if we could all get on the same page. Unfortunately not everything is black or white and a friend with benefits is neither... it's usually a solid gray.