Just one day when in my last year of school...
In my school, we had a system that mixed year groups into forms for 30 minutes a day. It was supposed to encourage interaction between year groups, but it didn't really work. On our last day of school, while we were waiting to be called to assembly, I was sat next to a girl from my year, 16 as well, and had a girl sat alone in front of me, who had just turned 15.
Now, the 16 year old girl (who I'll call B) was skinny, black haired with b-cup breasts and a firm ass. She never had either of her first 2 shirt buttons done up, and usually had a third undone too. On this particular day, she had a bright pink bra on, which I could see through her thin white shirt and from down her top, whenever I peeked. I think she noticed, but didn't care. She also had some very skinny black school trousers, which outlined her skinny legs and perfect ass immaculately.
The other girl (who I'll call E) was wearing a school skirt, one of those pleated ones, but she'd rolled it up to shorten it. A lot of her leg was visible. She also had thin, black tights on, which looked very nice. She must've had c-cup boobs, because every now and then I would catch a glimpse of some lovely cleavage (she wasn't too fond of buttoning her shirt up very well either).
Right, the actual story. So I was sat there on this hot day, waiting for something to happen in school, and I noticed that B was leaning forward a lot, doodling in a notepad. she had her head facing away from my, but between her chin and arm I had a perfect view of her bra, and could sneak peeks at her ass jutting out on the chair. I started to get aroused, and put my hand over my crotch to prevent anyone from seeing my erection. I ended up with gently putting pressure on my cock, which felt incredible as I squeezed harder and harder. Then, something magical happened.
B stood up and left to go to the toilet. When she came back a minute or so later, she got to our desk, and suddenly unzipped the fly on her trousers! She pulled them down a little, revealing a pink thong that matched her bra. As she was stood slightly behind me (you had to walk around to reach her seat) I turned my head a little and watched out of the corner of my eye, just staring at her crotch. I saw some black pubes just above her little panties. After about 10 seconds of adjusting her panties, she wiggled her trousers back up (both of these things seemed to last forever at the time), shaking that gorgeous ass whilst I stared. My dick was twitching in my pants, I knew I had to jack off soon.
B sat back down and I leant back in my seat, the hand closest to her in my pocket, squeezing the head of my dick. I did this for about 5 minutes, pausing to picture what I had just seen. I was having trouble not making sounds. I managed to slip my dick out of the front of my boxers and start rubbing it proerly, when the second magical moment occurred.
E got off her chair and grabbed something from her bag at the end of her desk. I got to watch her nice legs walk that short distance while I stroked myself. Then, she sat back at her seat. As she sat, her skirt lifted up a little, and got caught against her back and the back of the chair. With the way she was sat, the back of the chair was against the wall, and she was leaning on it sideways. In essence, one half of her skirt looked normal, nobody but B and I could see that it was up on one side. I stared at her round ass and white panties for a good five minutes while slowly stroking myself. Eventually, I felt like I was going to burst. I wanted to unzip and just spray my cum over both their bodies, but I knew I couldn't.
So I waited a few more minutes, until we went to assembly. On the way, I told my teacher that I needed the toilet and would be there in a minute. I went into the toilet and waited until there were no sounds in the hallway, and I was sure nobody would come in. I dropped my trousers and boxers in front of the row of mirrors and started touching myself, hard and fast.
It wasn't long until I exploded onto the counter below the mirror. 7 or 8 streams of cum flew from my engorged, throbbing dick, spattering thee blue surface with whitish lines of goo. I rubbed the head of my dick into a little puddle of the stuff, pretending it was E's ass or B's pussy I had just come on. After a few more moments, I realised I needed to go to assembly. I cleaned up hastily and went to the stupid assembly.
That was a great way to end my school career, and one of my best wanks and orgasms to boot!
I'll post more school-related stories, I have quite a few of them