Why do most guys wear loose pants?

Many men prefer to wear their pants looser, perhaps to defy their parents, teachers, or some kind of authority. Men may wear longer, loose-fitting pants because it is more comfortable. Also, most women do not find tight pants on men to be attractive.

It can also be perceived as a form of expression and defying the "norm," or the typical conventions of society. It all depends upon your own personal sense of style. Also; tight clothing tends to prohibit return blood flow. When your clothes are tightly fitted around the legs or waist, your heart has to work harder to help the blood return.