I was at my friends house and he has a hot younger sister a couple of years younger than me, she has huge tits and a nice ass. I went to his house one night to sleep over and his sister Courtney was up at the store and my friend was in his bathroom so I went into Courtney's room and took some panties and a bra out of her drawer, I wrapped my dick around them and started to wank myself. I came in the crotch and ass part of the panties and also in the bra but I was still hard as a rock, so I was snooping around Courtney's room and found her lip gloss so I started rubbing it all over my cock thinking how her soft wet lips have touched it then I came all over the lip gloss.
It was then time for dinner and Courtney had had a shower and gotten changed so I pretended to go to the bathroom but went to her room instead and the panties and bra were missing, I realised that she was wearing them and I was trying hard to hide my erection all through dinner.
After dinner we were all on the couch watching tv and I saw her bring out the lip gloss I had just shot my cum all over, with her not paying much attention I saw her wipe all my cum all over her lips and then she licked her lips, I was getting so hard again so I decided to take a shower, I went into the bathroom and saw Courtney's freshly worn bra and panties so I got completely naked and started wanking in her bra, I shot a little cum in her bra and then I started wanking furiously into her panties, I heard a slight noise but didn't pay much attention at the time, I was wanking right in Courtney's crotch in the panties and right when I was about to explode I saw the door open, Courtney and her mom walked in, I blew my load of cum all into the panties but it also shot straight through the material and onto her mom's stomach and right onto Courtney's thigh because she was wearing a skirt, it felt so good with them watching me but I quickly hurried home, they never told my friend and I see Courtney at school often and she gives me a slight look but I try to avoid going back to their house.