Guys can't catch a romance movie together?

Was chatting with a friend about this Singapore production 'The Leap Years', and he was complaining that he doesn't have any female friends to catch that movie with, and that 99% of his close friends are guys. And my question came, 'why can't you catch it with your guy friends then?' his reply was 'It's a romance movie, it's weird to catch it with a group of guys!' Why would guys think that it's weird to catch such movies with guy friends? They would think that it's a wrong thing to do. A couple of my other guy friends ever raised this issue too. They said that it's fine for girls to catch a romance movie together but weird for guys, just like nothing is wrong with 2 girls holding hands on the streets but when 2 guys are spotted holding hands on the streets people start to stare. Is this self-serving judgements at work? Or are they just going with the social norm? They do not what to appear in a way that they think is an improper behaviour in the society. Most girls would think there's nothing wrong for a group of guys to catch a romantic movie together, guys however think otherwise.