Does wearing tight underwear make your penis smaller?

If I wear tight underwear such as Nike dry fit will it make my penis smaller or not let it grow? I'm 17.
It will make you sperm count lower. This is permenant, so if you plan on having kids wear a loser boxer brief. As for the size, I don't it will affect that. Size is genetics.
try wearing cotton boxer shorts,cotton allows the penis area to breath whilst you sleep and during the day.Also because boxer shorts can be more lose fitting they give comfort and not irritation like tight underwear.
Um... no.

Underwear type has no effect on penis size bro.
No of course it doesn't - if it did we'd get none of these "I'm only 13 but I have 8 inches" on here every day!
Tag: Does wearing tight underwear make your penis smaller?