I've noticed that times I tend to get more huggy are moments when I am more inclined to react or act without thinking: when getting a particularly buggy bit of program to work, for example. Instead grinning, turning to him, and saying, "Thanks for your help", the sped-up version that barges past the internal censors is hug-and-kiss. Or when particularly tired, I'll tend to make more physical contact.
It could well be attention. I'd hope that it wouldn't be, but it might. I'll see if trying to implement extra safeguards against impulsive physical contact with him will do the trick.
When acting naturally with a close friend who I'm physically comfortable with, I'm usually all over them. Touch face, pet hair, give hug, slug arm, tickle, mime knee to groin, occasionally kiss to cheek for moments of extreme fondness or excitement. As Darkside and I are constantly sparring (playing Mercy, bonking over head, slug arm, punch stomach, kick ass, nerve pinch), I suppose I do classify him among people I'm physically comfortable with. Unfortunately, I wrote it as a subset of my normal physically-comfortable friendships, when actually it should be written as an overlapping-in-places but unrelated class.
Hmm. False perception of inheritance. Hmm.