It's an interesting thread. Two things are going on with me.
First, I am Italian, and have a very affectionate disposition. It's part of my family's way of expressing emotion. So even if I were not gay, walking with arms around shoulders, hugging etc. in public would be second nature.
But, second, when I love someone, I simply need to show it. Not in sappy displays, but holding hands, maybe sometimes discreetly, kissing in public (not necking, but kissing on the lips nonetheless) is something that is, for me, "person specific."
I am very close to someone with whom an annual outing is an SF Symphony concert around New Years. It is a symbol of the closeness of our relationship/friendship/companionship that we ofen hold hands during the performance, or while we have a glass of champagne at the break and are sitting just people watching.
Interesting that I came out late in life, and I am almost defiant in wanting to let the world know that we are close. He's been out forever, and is more circumspect about when/where to do this...but he always gives in, or initiates, because of the feelings of the moment.