I have to put my two cents in here. I have been going commando in jeans forever.

Occasionally, I will wear a thong with jeans...usually when I'm on my period (TMI...sorry).

But I hate the straight-across look in the butt with regular underwear. You're supposed to have a little curvature in the middle of your butt when you're wearing jeans. When you wear regular underwear with jeans, your butt cheeks go straight across from one side to the other...like you're wearing a full diaper.
Okay, okay, I know I may be a little paranoid about this.

I like wearing tight jeans that show off my curvature.

So kill me, okay?!?!! LOL