What kind of relationships does his side of the family have while he grew up? Did they take stock in showing expressions of affection? I, for one, know what its like to grow up in a family that rarely showed physical affection. It took my wife and her family to open my eyes to a whole new way to interact. Still it took several years to get to the point where I was comfortable doing it myself or even being on the receiving end.
It might be that he does not see as much value of doing the the "mushy" stuff as other do.
