Why do jeans tear up underneath?

That particular part is usually being constantly rubbed while walking. Unless worn by a bow-legged person.

Do you buy the same brand each time? If so, change brands. Sounds like a stress point, so maybe you are buying jeans that doesn’t fit your physique.

You have been buying inferior jeans. I have blue jeans that are many years old and still as good as ever….........in all places.

Try another brand and see what happens.

If this same situation occurs, the jeans are not the problem.

This same issue crops up with me from time to time.
I put it down to the fact that I go “commando” & have the testicles of a silverback gorilla.
Occupational hazard, as it were.

Is this your way of telling us how big your cock is?

Ha ha ha, no, this is not about my junk at all. I have Levis 501 jeans and my gf has Seven for all Mankind jeans which tear up as well in the same spot. I think I’ll get another brand. Thanks yah all!