I have this problem with my pants/jeans where they eventually rip in a weird place…inside of the thigh. Not in the crotch or butt, ever. And it’s not along a seam, the fabric itself begins to tear. I know how it happens, it pulls when I squat, and then eventually tears.
What I don’t know is how to repair it. So I end up with having to get rid of pants just when I’ve broken them in and they are fully comfortable.
I do have a sewing machine. If I sew up the edges of the tear, it only re-opens up again. I remember when I was younger my mother fixing pants with patches. I think patches are ugly and tacky…but a black patch on black pants would be OK, especially considering where the hole is - basically invisible to the eye unless you look close.
So how do you sew on a patch? Do you just sew around all four edges? Be aware while I can and do use my sewing machine often, I cannot do anything complicated. Straight lines and repairs is about all I can do (which I do plenty of!) So if it’s basic stitchery I can handle it. Nothing complicated, please!
I usually patch rips like this from the inside, sewing around the patch and also covering the rip with some extra zigzag stitches for reinforcement. As long as the thread matches fairly well, it’s less conspicuous than a patch on the outside–and you don’t have to match the fabrics perfectly.
Iron on patch, inside. Place a damp towel over the patch when you iron it to make it stick better. You could even do this in advance, when you first buy the pants to make them studier in that spot.
If it’s happening to more than one pair, they are probably ripping in that area because of friction between your thighs (sorry if that sounds personal, but it’s happened to me as well, courtesy of being hourglass-shaped!). Anything like a patch is more than likely going to rip around the seams because of this - the friction will still be there and it will be against a raw edge now.
I have a pair which successfully were altered through taking the fabric out of the pockets, and creating a new V shaped seam area through the crotch (hard to explain but ingenious seamstress, so you can’t notice when wearing). Might be worth taking them to a good alteration place and seeing what they can do.
Back when I wore pants, I always had to hem at least 4 inches, so I’d always have matching fabric. I’d reinforce the inside thigh area when I hemmed the pants up.
Generally, I’d wash the new pair of pants, then I’d machine sew lace seam binding an inch or so above where I wanted the new hem line, cut off the excess material, and hand sew the hem with blind stitches. Then I’d sigh, and move on to reinforcing the inner thigh area with the material I’d just cut out.
Hemming pants is a major reason why I don’t wear them any more.
I do this with my husband’s slacks all the time. Definitely sew the patch in from the inside and then zig zag over the tear. Iron on patches do tear and wear along the new raw edge, but sewn in patches have a softer edge and don’t do that as much.