I don't believe Roddick would even pay any attention to Novak if he didn't like him, He is American (specifically North) it's how the male version show same gender love.
Andy tries to do it with Federer too but Roger owns his ass and manages to just float above it like- "Hahaha look at you, i win. Always." to any of Roddick's smart ass-ness.
Novak likes to play with him... really they remind me of tiger cubs from the same litter wrestling.