it is a laundry related problem. Are you using various laundromats? even a home washer/dryer can mess up pants that aren't supposed to shrink--esp the dryer. buy them a little roomier and you can wash and dry them without fear.
also those partially stretch jeans lose their stretch in the dryer and can lose the weave almost.
I've had jeans tailored on occasion-- I bought these pricey jeans I adore in Dublin but they were always too big-- I got them tailored for 18 bucks. Worth it. they are my "Dress Jeans"
I know this is off subject, but I've been to Madurodam twice. I was really excited by the little sugar factory that gives you a tiny sack of sugar (an actual sugar cube) I stayed there for many hours each time. The tiny stock exchange, the nude subathers, the wedding party... -- I find it more fun than an amusement park. The first time I went it was pouring rain and cold--I was happy because no other tourists were there so I could go around and see everything--I was completely drenched, but happy.
I have a home washer and own no dryer.
I did bought two roomier but they are too loose around the butt and the legs. It sucks! Everything is either too big or too small.
Maybe I'll get them tailored too, that's a good idea.
If jeans are tight--let them air dry--not on the heater.
Duh, but the two roomier ones must be dried on the heater or in B's dryer! Otherwise it's better to not wear them at all, they're so unflattering.