I always tuck my shirt in my underpants and frequently the white elastic shows at the top of my pants. I get all kinds of flack for this as well as being called nerd,geek etc.and getting wedgies. Frankly with all the more serious problems in the world today I don't understand why guys make such a big thing about underpants. So mine show sometimes. Big deal!! Comments please.

i would rather see you in your underpants love an guy in tighty whities

Mmmmmmmmmmmm! What a terrific bulge, man! I think I'd rather see you without the undies!

OK, take this with a grain of salt. If your 39 (really?)you should not be getting wedgies. But I digress you have one of two options, 1) buy shorter underwear (low rise brief or such) or 2) get shirts that are classified as long. That means in the tailoring the actual shirt is about 4 to 6 inches longer.
Thus eliminating the eventual creep and pull out of your shirt. I look for long shirts as a matter of comfort but the happy side effect is no under pants showing. Hope this information is of use to you.
I want to apologize for the opening line in this post. It is judgmental and snide. The point of this question was to seek a remedy or advice, not hear my jibes. I am sorry. I lost sight of the point of this site and forum.

bump.

check out my pic on here, im real, curious too!

I see you're 39..if you don't get what the big deal about it is to see your undies then it is apparent you don't do much dating.....