Aussiebum briefs with fly

Understanding the Purpose of the Fly in Men’s Underwear

Boxer shorts are a popular choice of underwear among men for their comfortable and relaxed fit. However, despite their popularity, one part of boxer shorts often leaves people puzzled – the hole in front of the shorts. What is it for, and what is it called?

Many names have been given to the hole in men’s underwear, including penis holes, air holes, and pee holes. However, the most common term for this opening is the “fly,” similar to the opening on pants or trousers. The primary purpose of the fly is to make it easier for men to use the bathroom while wearing briefs or boxer shorts.

A brief history behind the Fly in Men’s Underwear

The clothing and underwear we wear daily can sometimes be mysterious, and it’s not uncommon for men to be unaware of the name and purpose of the opening in their boxer shorts. However, the hole is not just there without a purpose, and it has a name.

Over the years, the fly has undergone design changes to make it more user-friendly. The most common design today is a button fly that allows men to open and close the fly with ease. Some boxers even have a double-layered overfly that allows the flow to close itself.

Another area of improvement in the design of boxers is the pouch area. In the past, the pouch used to be flat and uncomfortable, but modern boxer shorts come with a roomier pouch that provides men with more comfort and freedom.

The purpose of the Fly in Briefs and Boxers

Despite the functional purpose of the fly, only about 20% of men who wear boxers actually use it to pee. Most men prefer to pull down their boxers and let it all hang out. This preference could be because going over the top of the boxers provides more comfort and freedom, albeit for a brief period.

However, when wearing dress shirts, using the fly is more practical than pulling down your boxers. Tucking in a dress shirt takes time, and using the fly eliminates the need to untuck and retuck your shirt after using the bathroom.

Besides the fly, pockets are another feature commonly found in men’s underwear. Smaller pockets are usually for carrying small items, such as spare change, while the larger pouch area is there to give men a more generous look and provide more comfort.


The fly in boxer shorts and briefs are there to provide men with an easy and convenient way to use the bathroom while wearing their underwear. Although only a small percentage of men use the fly, it remains an essential feature of boxer shorts. So, now you know the name and purpose of the fly on your boxer shorts.