Nipple

The beach is one of the few places there would be any actual double standard that works in a males favor, since males do tend to walk around with no shirts on at the beach, and females don't. It would also be one of the few double standards that does not work in a female's favor in life. Though if every female that went to the beach really wanted to walk around topless did so, there would be a lot of females to arrest hypothetically, since you don't often see any females arrested for walking around topless, or for exposure. The real question is would females want guys staring at their tits all day, which would be inevitable, and is the social conditioning that females go by when keeping their tops on. Nobody is staring at a male's nipples at the beach.