Forty Deuce and others have speculated about Fed and Wawrinka's "special" relationship. (ie: Refer to the picture.)
Here's what Fed had to say about the hugging, kissing, jubilant celebrating, etc..
"Well, I mean, the thing is, I can't just hug a stranger when I win singles (smiling). I could, I guess, but it's just not something you do. The guy would go like, Are you crazy or something? I would just rather not do it. I think that's the difficulties, you know, I guess in singles play, that you're all alone on the court. You win, you sit down. Going through the ceremony is quite different. I'm not the type of guy that's going to run up into the stands and start hugging my family and all my people who came. I never did that; I will never do it. It's a different approach to winning. In Davis Cup we've had some crazy moments, you know. People who know me, they know I'm very open and outgoing. It showed today. That's usually how I really am."