Since I started puberty and began masturbating a few years ago, one of the things I had always wanted to do was to start sleeping naked, but I was always afraid of getting caught doing it, so I never got around to it.
That changed a few weeks ago. One night I couldn't sleep and my boxers kept getting twisted around and bunched up, so I finally decided to get rid of them. I slipped them off and tossed them to the side, spread my legs apart and enjoyed the sheets rubbing every inch of my skin. Being so free I fell asleep pretty easily.
For some reason though, I woke up during the night and had a huge hard-on. I was laying on my stomach so it was wedged between me and the mattress, and the pressure on it felt great. Almost by instinct, I started wiggling around and grinding the mattress, loving the feeling of the underside of my penis rubbing against the sheets. I did this for a couple minutes before I felt my orgasm building, but I didn't stop and soon I was shooing a big, hot load underneath me. It felt so good I really didn't even know if I was awake or if I was dreaming, and I went limp and passed back out.
The next morning I found out I was awake after all, seeing the streaks of cum all over my sheets. I guess I had rolled around during the night, smearing it everywhere. Just seeing the mess I made got me horny again, and I started stroking myself, not even bothering to shut the door. Luckily my mom or sister didn't come down to my room, or else they would have seen me kneeling on my bed masturbating, shooting another load onto my filthy sheets. After I came I pulled my sheets up to hide the evidence, having to wait until I had the house to myself to wash them. That was a couple days later, but it did give me an excuse to blow my load without worrying where it would land.
It has now been about three weeks and I think I have slept naked almost every night since then. I found out that my mom did walk into my room a few days ago before I woke up and the sheets had been kicked off, completely exposing me. She didn't mind though, saying whatever was comfortable to me was fine with her. At least now it is in the open and I don't have to hide it from anyone.