First off i'm 19, and started puberty about 16. I've come along now, but got a few concerns. First, only during sex when i'm on top, or during masturbation, my testicles move up, out of my scrotum . It's not painful, but i'm still concerned. All i gotta do is tap it and it moves back.
Second not always but alot of the time, my scrotum seems tight. Even after a hot shower.