My friend and I went camping one weekend on the border of our town. Nothing special - we'd both just turned 14 and wanted to get away. We also masturbated all the time, and had only had our first mutual experience - wanking in his room together during our last sleepover, in the dark but light enough to make out each other's cocks. I was about 5" and quite thick back then, he was 6", long and thin. I think we both knew we'd do it again but this time it'd be a much more hands on experience.
It was a hot night and so in our sleeping bags we were already in boxers. I took mine off and threw my boxers to the foot of the tent and about five seconds later, he unzipped his sleeping bag and did the same - but left his sleeping bag open, his cock flopped out pointing up, towards me, hard as hell. I basically got hard in seconds and it pushed up against the sleeping bag. I stared at it and I could hear him laugh, and he wiggled it hands free. I grabbed it and realised what I'd done and let go straight away, apologised and got really embarrassed - I just did it, I guess.
He reached down at my chest, under my sleeping bag and grabbed my cock firmly. I gasped. He unzipped my sleeping bag and climbed over me, one leg either side of mine on his knees near my knees, and I grabbed his hard cock. We didn't say anything, just smiled. I was already about to burst but I held it together as he pointed my cock to the roof of the tent and slowly wanked me off. I started moaning loudly, knowing we were in the middle of nowhere. I let go of his cock about halfway through and he sped up, rubbing his balls and shaft on my leg. That sent me over the edge and I sprayed cum everywhere - I'd never done it before and I yelled out "oh my god!" A few times out of shock as much as relief.
He kept slowly stroking it but as I got really sensitive I grabbed his cock and, pointing up my chest, I jerked it as he ground his big balls against my thigh. In around 15 seconds his head flew back and he shot a load up my chest, neck and a little over my face. I just started laughing, he apologised and got his boxers and wiped me down. I didn't care, and said I wanted to do more like this later. He agreed excitedly.
Next morning, I wake up flat on my stomach to him rubbing his cock up and down my ass, holding me by the hips! I was shocked at first but I got really hard, feeling him hold me and use me - I signalled I was awake by looking over my shoulder and he grunted hard, cumming up my back. Needless to say I returned the favour, and we started doing this kinda thing a lot more often, in and out of tents!!