Hey, this happened when I was 12 or 13.
I was at my friend Jacob's one night for a sleepover. He was very suprised as he thought I hated him as he had told my GF that I didn't love her anymore and for some reason she believed him and dumped me. (I was planning revenge on him that night).
The night began watching a film (Shrek, I think) when he said he was going to bed so I said I would join him, his parents had to leave early tomorrow morning so we had planned the day! (I had different plans though)
I got into my sleeping bag and went to sleep, put my headphones on and set an alarm for 3am!
I went to sleep in my PJs and he slept in his red M&S briefs (a bit like these http://snipurl.com/1ox04g)
At 3, I woke up and reached for my bag containing Belts, Long Sports socks. I tied his legs to the bottom bed posts, arms to his top bed posts, placed a eye mask over his eyes but left the gag till he woke up.
I went back to sleep, we both then woke up at 10am. when he tried to move he couldn't that's when he started to try and shout so I went into his rawer and pulled out some skimpy stripy 7-8 year briefs and stuffed them in his mouth then cleave gagged him.
I lifted his bed sheets and removed his eye mask he mmmmmmppppphhhhhhhh'd for 2 minutes then gave in
Our fun had only just begun!