Well, the only time i've been caught whacking was the start of a relationship for me with a girl who's pants i'd been trying to get in for a couple years.
Sorry, but this will be a little long, so I can tell the story and explain.
I was 17 and she was 19, a senior, and as hot as fire, redheaded, green eyes, and a body that had all the guys drooling and wishing. I'd asked her out several times, only to hear, "No thank you, you're too young", or, "You can't handle this hot stuff", or, "You don't have enough dick to do anything for me". You see, I was quite overweight, and everyone use to say that a fat guy had a small dick, since "Things don't grow good in a shade"...haha.
Anyway, this went on for about 2 years, as we both were in the band at high school, and I would jack off to the thoughts of her and me, or see her in a bikini, which would give all the guys, and some of the adults, an instant hard on. When she would sashay by me, shaking her money maker, knowing it turned me on and made me horney, I would have to make time to sneak off to the bathroom or something and jerk off.
Well, the band went on a trip one fall to a band contest in Florida. We had several hotel rooms, with the normal guys on one floor, girls on anothe floor, and lots of chaparones to keep us apart. But, during the evenings before bedtime, many of the guys and gals would come into each other's rooms and watch tv, listen to music, and generally just be there....with a chaparone watching, of course. Only, this evening, everyone was on the beach, except me, who had come in to jerk off since this girl had me so turned on I couldn't stand it. I was in the room, alone, with the door closed, but in the bathroom with that door open. I didn't even think about the balcony and that door being open, or that anyone would come in, as they were all playing volleyball, or swimming.
Well, here I was jerking up a storm, and was about to cum in a piece of toilet paper, when a hand touches my shoulder. I almost freaked out, and as I turned to see who it was, my cock decided it was time to blow it's load, and I just turned around to spew my sperm all over....my redheaded hottie. I was scared to death from being caught, especially with someone touching me when I thought I was alone, yet when I turned around, I just started cumming. I hit her on her chest with the first shot, then the stomach with the next shot, finally with two more shots on her legs and feet, almost as if the pressure was high, then got lower on each shot.
I couldn't believe it, and she just stood there, shocked at first, with cum on her, looking down at my cock. At first, I said something like, Oh my God, and I'm sorry, and then finally the fact that I was alone, I thought, and my privacy had been invaded, I started saying something to the fact that she should have knocked. All this time, she just stood there, and then a smile came over her face, and then she did something I was totally unprepared for at that time....she grabbed me by my dick, pulled me to her, and started french kissing me, her left hand rubbing my cock all this time. This lasted for about a minute or so, then we broke our kiss, she stepped back, my cock still in her hand, cum still all over her, and she looked at me and said the words that I will remember for the rest of my life. "I love it when a guy cums on me. That's so hot and makes me so horney." She let go of my cock, told me she was going to have to clean up, she wiped off my cum with a towel, and left the room, and me.
I thougth for sure, yeah, she's gonna tell everyone about this and they'll all make fun of me or shun me or something, but she didn't. Instead, only a few hours later, she started hanging around me, coming into the room I was in to talk to me, and after the initial shyness and worry of her telling about this, I started to talk to her. From then on, we were close, and after we got back home from the band trip, she and I started dating, much to the shock of many of the guys and even her friends. Such a hottie and a not really fat, but overweight average looking guy together, dating, was unheared of, but she and I were unseparable for about 5 months, until she graduated.
Oh, and yes, she did change her mind about 'things growing in a shade' and about me having a small dick, since she saw the truth and liked what she saw, not to mention the painting with sperm she got. And, during those months, we had sex several times, but she always wanted me to cum on her instead of in her. It seems she had a cum fettish, and I was the start of it, and the one who she wanted to cover her all the time. I got inside her twat many times, or a blowjob, but always when it came time to cum, she made me pull out and cum on her face or tits or stomach...wherever it landed was fine.
After she graduated, and went to college, I never saw her again, and to this day, don't know whatever became of her. But I will cherish those days forever...and that hot body covered with my cum.