What Are The Holes in Men's Underwear For?

Have you ever wondered why men’s underwear has a hole at the front or where that design originated? Here's a quick guide to everything you need to know about men’s underwear designs.

Many men’s underwear styles feature a front slit or hole, sometimes secured with buttons. This seemingly small detail is often taken for granted, but has it always been a part of men's undergarments, and what is it for?

The primary reason for this detail is to provide men with quicker access when they need to pee. But is that the only reason? Are there other purposes for this zip, hole, or pouch? We’ll explore these topics and answer the question of "what are the holes in men’s underwear for?" as we dive into the design and function of men’s underwear. Enjoy the read!

The Fly

Nope, not the 1980s movie starring Jeff Goldblum, but the hole at the front of men’s pants and boxers is also called a fly! The purpose of the fly is to allow men to pee while wearing boxers without having to pull down or remove them altogether.

There are two main types of flies found in the hole in your boxers. The horizontal fly offers the most comfort and protection, keeping everything securely in place during physical activity. The vertical fly, which may include buttons, provides easier access for urination. However, without buttons, it can lead to accidental exposure and can be more challenging to navigate for left-handed individuals.

The ALPHX® Union Pant with 120 Degree Button Fly Closure

You might notice that some designs, such as those sold by ALPHX® feature a more prominent area at the front, known as the pouch. Contrary to popular belief, a roomier pouch isn't an indicator of larger genitals but is designed for comfort, and support. The fly is an additional feature that makes it easier to relieve oneself quickly. 

ALPHX® Comfort Class Trunk Modern Fit with Contoured Pouch

Men’s Underwear Design – A History

The fly or slit in men’s underwear is a relatively modern development, introduced in the 1800s. Before this innovation, the area used to be flat with no convenient access, making bathroom breaks cumbersome. The introduction of the fly provided men with greater definition, comfort, and ease of access. This design quickly became popular worldwide.

But why do we use the term fly?  Well, over time, fly came to mean attached by one edge like a flag or a banner flying from a pole or a rope. With this in mind, 19th century tailors used the term “fly” for a flap of cloth attached at one end to cover an opening in a garment.  The fly was born, and the term has been used ever since.

In the 1930s, Arthur Kneibler further revolutionized men’s underwear by creating the iconic ‘y-front’ design for his boxer shorts. This flap at the front made bathroom visits even more convenient while ensuring comfort without restricting sensitive areas.

These innovations moved men's underwear forward considerably.  Historically, men’s underwear was quite rudimentary. The Ancient Egyptians wore linen loincloths called Schenti, tied at the front. This design, also seen in Native American and Grecian cultures, was uncomfortable and impractical, proving to be restrictive and difficult to manage.

Men’s Underwear in the Modern Day

Since the 1930s, men have enjoyed the convenience of easy access with the introduction of the fly in their underwear. But do all modern men’s undergarments include this practical design? While the fly offers men convenience to relieve themselves, they do not offer much in the way of support.  Typically fly front underwear maintains the flat front of old, which means that everything is left hanging if you will.  

Enter the pouch. The pouch design creates a “cup” that is shallower at the top and deeper where you need it to cradle and support your important bits when wearing.  For many, this provides a more comfortable wearing experience under trousers.

Today’s trouser designs have also made the pouch more popular. Most pants today are designed to sit on your hips as opposed to at or above your belly button in times gone by.  Underwear has followed suit, meaning that today’s underwear has a lower rise than in the past, eliminating the need for the functional purpose of the fly. Translation:  it’s easier to pull the waistband down than to use the fly. In fact, data shows that today only 20% of men use the fly for its original purpose.

Participate in the survey: Do you prefer men’s  underwear:

Boxer Briefs: are the most popular types of men’s underwear today, offering a combination of the support of briefs and the coverage of boxers. Boxer Briefs may have a pouch or fly and can come in different inseam lengths from 4 to 8 inches or longer. Boxer Briefs can be made from a variety of natural or synthetic fibers with cotton and cotton blended fibers making up 60% of the market.  There has been a recent trend toward using other plant based fibers for softness, and breathability such as modal, bamboo, and lyocell.

Trunks: are the fastest growing style of men’s underwear. They are essentially the same style as boxer briefs with a shorter leg. You can find trunks with a 1.5 to 4 inch inseam.  Choosing between boxer briefs and trunks comes down to how much of your leg do you want covered.

Briefs: trace their lineage back to the 1930’s and were inspired by the jock strap.  Essentially a brief is a jock strap with a filled in seat.  Briefs offer support, full coverage, and allow for complete leg freedom. As with the other styles they may be found with or without a fly.  

Union Suits: cover the entire body and are typically worn as layering garments in cold weather or for lounging. Because union suits are a one piece garment that covers both halves of the body, they usually feature front and back access, allowing easy bathroom use without needing to remove the entire garment. Long Johns or union pants are the bottom portion of a union suit and as with the other styles discussed, may come with or without a fly.

In conclusion, the fly was an innovation in men's underwear that brought functionality to the category.  As trouser rises became lower, the need for this functionality became obsolete and the pouch which provides greater comfort and support eclipsed the fly in popularity.  Today, you can find underwear with both pouches and flies in the marketplace.  Ultimately the choice comes down to personal preference.