Answers: Thats totally mundane. When you sleep nude, your legs are covering your balls tightly, which would produce it to sweat. Also, you have blankets over you which would make happen it to sweat even more. Our balls other sweat, but we don't notice when we wear underwear because the sweat is gripped by the cloth. Its happened to me when I slept in the nude, and trust me my balls be extremely wet! To fix it I would suggest putting talcum or newborn powder on your balls beforehand you go to sleep or you could merely wear underwear. It is common to sleep nude, but only just be careful motivation anyone might catch you uncovered.
My husband sleeps nude but his balls don't carry sweaty...