Underwear With or Without a Fly – Pros and Cons

Short answer: Underwear with a fly gives you a practical opening at the front, while models without one lie smoother and have fewer seams. Neither is objectively better, it comes down to habit and comfort. Both types come in soft bamboo viscose that keeps you dry all day.

The advantages of a fly

The fly makes a trip to the toilet quicker, and that counts most in workwear, outerwear and anywhere there are several layers in the way. Many men grew up with the detail and will not do without it. The drawback is an extra layer of fabric and more seams at the front. See both types under bamboo underwear for men.

The advantages of models without a fly

Without a fly the fabric lies completely smooth, and there are fewer seams that can bother you. That gives a cleaner look under close fitting trousers, and most tights and modern boxer briefs therefore come without. If you have sensitive skin, fewer seams in a damp area is a real advantage and not only a matter of looks.

How the fly is constructed

The classic fly is an opening with an overlapping layer of fabric, so it sits closed on its own. Some models use a Y shaped construction with two overlapping layers instead. Both work, but they put three to four layers of fabric at the front against one layer without, and on a hot day you notice it.

When a fly makes most sense

If you work in dungarees, overalls, braces or heavy winter clothing, the fly saves real time several times a day. The same goes for long drives and anywhere you cannot simply pull your trousers down. If your day is ordinary trousers with a belt, the time saved is so small that it rarely decides anything.

When no fly is better

For training, running and cycling the model without a fly wins, because fewer layers mean less that can fold and rub as the body moves. The same goes under close fitting trousers where an extra layer at the front can show. If you need one pair for activity, choose one without a fly and with a leg.

The material matters more than the detail

Whatever the model, the material is the choice you feel most. Bamboo viscose moves moisture away from the skin and out into the fabric where it evaporates, and smooth fibres glide over the skin instead of scratching. See the whole range of bamboo underwear for men and compare the models from there.

Try both before you decide

Most people have a habit rather than an opinion, and the habit often comes from the underwear they wore when young. Buy a single pair of each type in the same brand and the same size, wear each for a week, and then you know. That is cheaper than buying a pack of the wrong kind.

Fit decides more than either

A fly that sticks out is almost always because the pair is too small at the front, not because the fly is poorly made. If the rise and the waist are right, the fly lies flat and does not show through the trousers. If the pair sits wrong, both types bother you, just in their own separate ways. See also bamboo clothing for sensitive skin and bamboo underwear for men.