I don't really get the question. I wouldn't do anything. It seems like he was out with a big group, including his wife, and for whatever reason, wasn't particularly responsive or was made uncomfortable by your comment. What do you mean by you didn't realize his arm was around his wife-- you wouldn't have said it or touched him if you did?
I would just move on and when I saw him at the next neighborhood function, talk to him and to his wife like I always do.
ETA: I guess I'm also a bit confused because you titled it "guy friend issue." Was he a boyfriend or something, or he was just a friend from high school? If he and his wife and family came to see you, were you not saying hello to both of them when you saw them out at the restaurant? If they're neighbors who you see at neighborhood functions, I guess I'd be looking at both of them as friends, as they're married and, I assume, come to neighborhood functions together or as a family.
Jen, mom to my silly monkey, 10/06