Why Do Guys Wear Underwear Under Their Swim Trunks?

why do guys wear underwear under their swim trunks

Girls might be wondering why guys sometimes wear underwear under their swim trunks. Good question. Funny thing is, most guys don’t know the answer either. Based on anecdotal evidence, it seems like most guys have never really even thought about it.

The way it starts out and persists is that at some point, they just noticed that other guys do it, so they do it themselves because they want to conform or they just assume that there must be some good reason why other guys do it.

If you were to really press a guy to answer this, we start getting to some real reasons. First, many guys believe (perhaps wrongly) that wearing boxers can reduce chafing, especially if the inside of their swim trunks don’t have a mesh liner.

Another reason is that, due to how similar swim trunks are to shorts, to them it feels like they are wearing regular shorts. Since guys usually wear underwear when they wear shorts, they also feel like it’s more “natural” to wear underwear beneath their swim trunks.

Next, guys might wear underwear under their swim trunks due to feeling self-conscious. When swim trunks get wet, they cling to their body, making their bulge highly visible. By wearing underwear, it makes the bulge less pronounced. It’s actually very considerate of guys going the extra mile so they don’t seem like voyeurs showing off their private parts.

There are even more reasons and nuances to this topic, and in this article, we will discuss the pros and cons of wearing underwear under swim trunks to better understand why guys do it in the first place.

Do most guys wear underwear under their swim trunks?

This is a question that is difficult to answer as there haven’t been any surveys conducted and there are no statistics to draw any reliable conclusions from.

It seems like in some areas, or among various social groups, there’s a wide variance on what is considered socially acceptable or not.

The pressure to conform is high, especially among teenagers, where the fear of getting ridiculed can cause guys to follow the trend of wearing underwear under their swim trunks without knowing exactly why.

Conversely, there are some groups where it would be considered weird to wear anything under their swim trunks because the swim trunks basically are your underwear in an aquatic setting.

There are also some groups or communities where people just don’t really care if guys wear underwear beneath their swim trunks or not.

I find that this “issue”, if we can call it that, most commonly affects teenage males. The older one gets, the less they seem to care.

I’m making this observation based on the absolute shamelessness of some of the older men in the changing room who are unafraid to walk around completely naked; I doubt these shameless, nay, enlightened men are deliberating if they need to wear something under their swim trunks or not.

Reasons why guys wear underwear under their swim trunks

boxers under swim trunks

Everyone else is doing it

If you haven’t had the chance to ask a guy why he does this, you’d just assume that he has some kind of good reason that you just don’t know. Well, when you realize that mostly only teenage males are doing it, and they aren’t exactly the brightest demographic, then it becomes very obvious that you’re not the dumb one.

A deceptively simple and arbitrary reason why guys wear underwear under their swim trunks is that one guy saw a bunch of other guys doing it, and so he joined in because he doesn’t want to stand out. And that keeps on perpetuating this ridiculous belief that somehow wearing boxers with swim trunks is the right thing to do.

Unfortunately, as we mentioned, peer pressure is at an all time high among teenagers. Plus, the fear of being left out or ridiculed is high, so I don’t really blame them for following the crowd because I was guilty of it too.

They want to hide their junk

When clothing gets wet, it clings onto your body a little too tightly. It leaves nothing to the imagination, and everybody can see a good outline of your body. This has been the cause of many humiliating situations where someone’s bulge becomes very clearly visible.

This is an issue for a number of reasons. One, many guys are self-conscious about the size of their junk. Unfortunately, many guys care too much about how big (or small) they are down there and many guys think that they are somehow inadequate.

They think bigger equals more masucline, more dominant, and that it impresses the ladies, and that a smaller one does the opposite. It’s a pressing issue even into adulthood, but that’s beyond the scope of this article.

It doesn’t help that the water is cold, and cold leaks to shrinkage, and thus it sets them up for a situation to get ridiculed. That can lead to awkward situations like the one shown in the video below:

The second issue is a more practical one: guys don’t want to come across as being a voyeur. It already doesn’t help that, between guys and girls, guys are often considered predators and not given the benefit of the doubt. All it takes is for a girl to complain about a guy “exposing himself” and the guy could be in deep trouble.

Another problem that is almost exclusively a problem that teenagers face is the threat of “pantsing”. Some guys like to “prank” (using this term loosely) others, and an easy way to do that is to pull down the other person’s shorts or pants and expose their private parts for others to see. A lot of guys feel safer if there was another layer underneath to cover them.

Thus, by wearing boxers, the outline of their private parts becomes much less obvious, and they feel more comfortable knowing that they have extra “protection.”

They treat the swim trunks as shorts

Depending on the size and design of a pair of swim trunks, they could easily pass as just a regular pair of shorts. Let’s just ignore the fact that guys could just wear a regular pair of shorts instead of swim trunks and keep on going with this train of thought.

If you find yourself an article of clothing that fits you comfortably and looks nice on you, do you really care if it’s not being worn as intended? For instance, if you’re wearing something designed for another gender, or you prefer an oversized fit, or in this case, you’re wearing swim trunks as shorts?

Some guys just want to wear their swim trunks around in the summer like regular shorts, and if they want to, they can spontaneously jump into the water. If guys are wearing swim trunks like regular shorts, then they are also going to be wearing underwear beneath them.

They want to prevent chafing

Out of all of the reasons listed above, the primary reason guys wear boxers under their swim trunks is to prevent chafing. This solution is debatably effective because boxers can create problems of their own.

Many guys think this is a great idea when they are on land and still dry. The problem arises once they are underwater and their boxers soak up all of that water. Suddenly, it will feel like you are wearing a wet diaper that is weighing you down and potentially contributing to more chafing. We will expand on this point in another section.

Look, we are not the underwear police, but arguably all of the reasons provided for wearing underwear under swim trunks are not great reasons. With that said, if wearing underwear under your swim trunks works for you, then more power to you. We are leaning towards not wearing anything under the swim trunks, and in the next section, we discuss our reasons why.

Why you shouldn’t wear underwear under swim trunks

Most swim trunks have mesh liner

Most swim trunks, at least the ones I’ve been wearing, have an inner mesh lining. The point of this is to act like boxers by providing you support and reducing chafing whilst keeping water from getting absorbed.

If your swim trunks have mesh liner, wearing boxers just adds yet another layer and will make your swimwear feel more uncomfortable.

Boxers absorb water

Most boxer briefs nowadays are made up of cotton which can lead to many problems when they are wet. For this reason, experts recommend that you do not wear boxers under your swim trunks, regardless of how comfortable you think they feel.

The reasons are that cotton does not dry very fast, will absorb a lot of water, and can contribute to chafing when wet. Let’s unpack each of these points.

Cotton is capable of absorbing a lot of water, so you will feel like you are wearing a soggy diaper. The extra weight can slow you down and feel uncomfortable once you’re out of the water.

This leads to the next point: cotton does not dry very fast. If you are in a beach setting where you are going in and out of the water, you will notice how annoying (and chilly) it is that your swim trunks are always wet, and that’s because the water absorbed by the boxers is seeping into your swim trunks.

Lastly, if you are wearing boxers because you think it helps prevent chafing, sorry to break it to you but wet boxers can contribute to chafing. When cotton is wet, it will stick tightly against your skin and increase friction, increasing the likelihood of chafing.

Your boxers will wear out quickly

Underwear is not designed to be worn underwater. Thus, constant exposure to salt, chlorine, or any other chemicals in the water from the pool or ocean can drastically decrease the lifespan of your undies.

I don’t know about you, but I buy and wear high quality boxers because nothing is more uncomfortable than cheap ones that don’t give my junk any room or constantly roll up. It would actually make me very annoyed if my nice boxers started to wear out because of something silly like wearing them into the pool when it’s not even necessary.

Swim trunks, on the other hand, are designed to withstand constant exposure to these conditions and that is why they are the appropriate article of clothing to wear into the water, not your boxers.

It looks silly

How many of you remember the fashion trend where teenage males would sag their pants? Maybe it’s still a thing, or maybe you are out of the loop on what this is. For whatever reason, young males would wear their pants or shorts beneath their waist, revealing their boxers. Google “sagging” if you don’t believe me (or just read this Wikipedia article).

Well, when I see someone wear underwear with their swim trunks and the waistband is visible, it evokes the same feeling I get when I see young men sagging their pants, which is: why?

Who knows, maybe I’m the crazy one and sagging is considered a good look where you’re from, but I personally think it’s silly looking.

It’s not good for the pool

You know how you’re supposed to shower first before you enter the pool? You might think you are cleaner than the average person, and that that cleanliness extends to your underwear, but unfortunately that’s the kind of thinking that makes public pools dirtier than they ought to be.

You may not have realized it, but your underwear has probably absorbed a lot of sweat over the course of the day (among other fluids). It’s filled with plenty of bacteria and you don’t want to bring it into a pool. This reason alone should be sufficient for you to not wear your underwear to the pool.

Next, the chlorine will break down the cotton fibers and degrade your boxers, as we mentioned above, and this can result in cotton fibers messing with the pool filter.

Parting words

In this article, we covered the reasons why many guys decide to wear their underwear beneath their swim trunks into the water. We also discussed many reasons why it is a bad idea to do so.

If you are wearing swim trunks to the pool because you think it can protect you from chafing, or that you just don’t want to stand out, these are not the greatest reasons (and may not even be effective).

As for the downsides, you can potentially increase chafing, introduce more bacteria into the pool, have trouble drying your boxers, and feel like you’re wearing a wet diaper everywhere. Trust us, it’s more hassle than it’s worth.

With that said, we are not the underwear police, and you can do whatever makes you feel comfortable. If you’re just someone wondering why there is a strange phenomenon of guys wearing underwear with their swim trunks, hopefully you understand a bit more now.

Photo credits: Images Alight (CC BY 2.0)