Always remember to clean up after yourself
This happened when I was thirteen or fourteen as I had recently discovered masturbation.
My mother had gone out and I was supposed to be asleep already. After she left I got out of bed and was horny as hell.
I got my Vaseline and rubbed it on my dick and started to stroke. Man I was so horny and I wished I had a Playboy or Penthouse magazine to look at, but I didn't want to orgasm yet so I went into my mom's room.
I don't know why but I opened her underwear drawer and looked around inside. I found a tiny little string bikini. I lay on my mom's bed and rubbed the bikini on my stomach, enjoying the feel of the lace against my skin. I think the feeling of arousal was heightened as I knew I shouldn't be in her room, much less playing with her panties.
Then suddenly my balls were going to explode and I was going to come any second. I jumped up and ran into my mom's bathroom. As I ran my sperm started to travel up my dick and I knew I couldn't make the toilet so I pointed my dickhead at the sink and let loose with about six streams of sperm (I usually shoot five to six streams). It felt so good as I stroked and squeezed every drop out of my dick.
I wiped the Vaseline off my dick and hand then put away her panty. I went back to bed feeling drowsy now. As I started to drift off to sleep I heard my mom come in and go to her room. Then a few minutes later I kept hearing the bathroom faucet turning on, then off. On then off. On then off.
What was she doing with the faucet? Then it hit me, oh my God she was trying to wash my cum down the drain! My mom was trying to get my sperm out of her sink!
I was horrified and I didn't fall asleep for several hours. The next morning she didn't act unusual or say anything to me as she must have been embarrassed herself.