Hehe, hopefully I'll get laid soon and won't have this problem
but yeah, I've noticed that wearing jeans makes the "problem" not as noticable, but when I'm sleeping in boxers next to a girl, esp with her butt facing my crotch, it can be embarrassing. I need to tuck things in or feel kinda embarrased.
Anyway, I find it strange how in porn guys can be limp while girls are teasing them, or even beginning to nibble and kiss their penises. I know I would be more ready to go then they are :P