I'm a big fan of comedy and I enjoy watching stand-up on TV and also going to live comedy gigs. One of the things I like about TV comedy are the crowd shots. They always try and intersperse the comedy with shots of the audience and they try very hard to pick their subjects. The people who get the close-ups have to be attractive and also visibly enjoying themselves...that's not who I'm looking at though...I'm scanning the background audience. No matter how much a knot of people are enjoying themselves there is always one person no more than 4 seats away who is sat there stony-faced, arms folded, thinking "this isn't funny in the slightest."
The main thing I've noticed though, is that when people are laughing they almost always look toward their partner. There doesn't seem to be a hard and fast gender divide; sometimes the man looks toward the woman, sometimes the woman to the man. I'm not completely sure why this is. I think it is part of NT behaviour to share experience and ensure your companions are also enjoying themselves. Maybe the glance is in case the couple want to add any in-jokes of their own to the proceedings. When I go to see comedy and I find something funny I just laugh...I have never had the desire to look toward anyone I happen to be with.