I hate this sort of repair...
A decent brand of jeans (Armani...unless they're fake)...and they seem to be in a good state. They're not threadbare or worn, so it's a slightly odd and quite dramatic tear.
I checked to see if I had any spare denim in this colour but have nothing suitable, so have decided the best and neatest thing to do is a darn.
So...first thing is to open all the seams to be able to work on it properly.
Starting with the inside leg seam...next undo the seam beneath the fly....then unpick the fly facing a little to be able to move it out of the way.
The damage needs to be backed with a bit of fabric. I have used a scrap of Egyptian cotton. It doesn't need to be thick fabric. After it's darned, it will feel more rigid, so thick fabric will make it too stiff.
This fabric needs to be tacked onto the back of the damaged area. You need to try to get the rip as close as you can to its original shape so the jeans will fit back together again when you restitch all the seams.
I also tacked across the frayed jeans threads to try to hold them as flat as possible. I snipped some of the worst of the straggly white threads off these too.
Try to match a thread as close in colour as possible....and...Darn....
When you're done, remove all the tacking threads and trim off any excess backing fabric.
Pictures show from the back, where it's clearer how I've stitched it. The white threads are always annoying on jeans. I sometimes feel I'd like to colour them in to hide it
And then you just need to stitch all your seams back together.
All done. Not an especially enjoyable or nice job, but it's better than flashing your crotch!
Sandra.
xxx