Yes adult men can wear shorts. It’s tough to make them look good but not impossible. There are three basic rules.
1. Keep them short
This does not mean 70’s short but anything between 8″ and 11″ is a good working amount. You want them to fall just a bit above your knees. Believe it or not, the area where your thighs meet your knees has a good amount of muscle tone and it is attractive to most women. It’s also still a relatively rare sight to spot a man with shorts that stop at his thighs instead of his shins. If you’re self conscious go with 11″ inseams. The more daring can go shorter but you really don’t want to do less than 8″.
2. Keep them slim
Shorts have a tendency to make a man’s legs look like toothpicks. It’s the reason most men opt for longer shorts as it elongates the whole look and makes their legs look a more consistent width. A better option is to keep them shorter and nice and slim through the thigh. As shorts are more casual, you won’t want them to be so slim they restrict your movement, but you do want them to follow the natural lines of your legs. Shorter shorts that are slim make your proportions looks more natural.
3. Keep them simple
Avoid cargo shorts like the plague. There is nothing that screams foppish frat-tard like a pair of cargo shorts. Yes slim cargo pants are having a moment but that has not extended to shorts. They’re already boyish enough that you need to keep the shape as simple as possible to dress them up. The same goes for any patterns. I love madras as much as the next guy but shorts should be solid. Yes they can be in go-to-hell colors, but you want them solid.
Here’s an example of exactly how a good pair of shorts should look.