The group photo with the bride and groom from yesterday's wedding has finally landed in the family WhatsApp group. You zoom in to make sure your eyes weren't closed. They weren't. The real problem is at your hips: both side pockets of your trousers are gaping open, sticking out left and right like a pair of fins.
Yet in the mirror before you left, everything looked right.
Your first suspect is bound to be the stitching. Hold off on that accusation for now. More often than not, the pocket is perfectly fine. The opening gapes because something elsewhere in the trousers is pulling on it. All that's left is to work out where.
Why Side Pockets Are the First to Flare Out
A side pocket opening sits right on the line of your hips. That's the area that takes the strain first, whether it comes from trousers that don't quite fit or from whatever you're carrying in them.
A pocket opening is basically a slit in the fabric. As long as the fabric around it is relaxed, the slit stays shut. The moment that fabric pulls taut, the slit is the first thing to spread open.
So think of a gaping pocket as a warning light on a car's dashboard. The light comes on because something in the engine needs checking. Re-sewing the pocket without finding the source of the pull is like covering that light with sticky tape.
The pull can come from three places: what's in your pockets, the size of the trousers, or the way the pocket itself is made. Check them in order, starting with the easiest.
First Test: Empty Your Pockets and Stand Still
Take everything out of your pockets, from your wallet and phone right down to the parking ticket folded into a corner. Put the trousers on, then stand still in front of the mirror.
If the openings shut again, case closed: the culprit was what you had in them. A thick wallet and a big phone really do drag the fabric down, especially if you sit for a long time with everything still inside. Try moving one of them to your bag and see what changes.
There is one exception. Trousers that have been stuffed with heavy things for years can stretch out around the pockets, so the openings keep a slight gap even when they're empty. Apart from that, a pocket that stays open once it's empty means the cause lies somewhere else.
Empty Pockets Still Gaping? Look for Pull Lines Across the Thighs
Strain from the wrong size rarely shows up on its own. Look for other signs close by, such as fine horizontal lines across the thighs, or fabric around the crotch that feels tight. If those signs are there, the open pocket is just part of the same problem: your hips or thighs need more room than those trousers are giving them.
Check the rise as well, which is the distance from the waistband to the crotch. If the rise is too short, the waistband gets pulled slightly down from where it should sit, and the fabric around the pockets goes tight.
Trousers in the right size are easy to spot. The fabric falls smoothly from waist to thigh, with no pull lines running in any direction. Take chinos, a casual trouser with a cut neat enough to wear to the office. When you try on a pair of black chinos, look at the front just below the waistband. If they fit, the fabric there is relaxed and the pocket openings sit flat without you having to smooth them down.
The cut you choose matters too. Fits that leave enough room through the hips and thighs, such as straight or athletic, generally make gaping pockets less likely. A slim fit can lie flat as well, provided the size really suits your build. There's a short explainer on what each fit means in our Help Center.
Signs the Pocket Construction Is the Real Problem
Sometimes the pocket really is to blame, and the signs are fairly clear. The opening already gapes while the trousers are still hanging in the shop, before anyone has worn them. When you put them on, the fabric around it is smooth and free of pull lines, yet the opening still refuses to close. The same thing happens in every size you try.
The usual cause is a pocket placed too far to the side, or an opening cut too wide.
Luckily, this kind of case is the easiest to sort out. A tailor can shift the pocket slightly forward or make the opening smaller. It's quick work and usually costs very little. Since you already know what's wrong, your request can be short too: "Could you move the pockets forward a little, please?"
Re-sewing only helps when the pocket itself is the problem. If the pull is coming from your hips or thighs, the fabric stays under tension, and a freshly tidied pocket opening will just spring open again.
How to Test the Pockets When Trying On New Trousers
In the fitting room, don't just stand there and turn from side to side in front of the mirror. There are two positions you need to try.
First, the same test you did at home: empty pockets, standing still. The openings should close on their own, without you pressing or smoothing them down.
Second, sit down for a few minutes. Your hips spread when you sit, so a little gaping in this position is still normal. What matters is the moment you stand back up. A healthy pocket lies flat again straight away. If it stays open, go back and check for those signs at the thighs and crotch.
To make the comparison clear, bring two sizes in at once, say the dark grey chinos in your usual size and the one above it. Going up a size can help if the pull is coming from your hips or thighs, as long as the waistband doesn't end up too big as well.
If the pockets gape in both sizes, what you need is a cut with more room. For comparison, repeat both tests in a pair from the Ankle Prime line, then see which pair keeps its pockets flattest on you.
Those two tests take only a few minutes in the fitting room. After that, when the next wedding photo lands in the family chat, you'll only need to zoom in to check your eyes.