When I was in highschool I used to house-sit for neighbors and friends a lot, everyone knew me as a very responsible person and they knew they could trust me to take care of everything, be it plants, pets, or whatever.
Anyway, one thing I liked about this was the chance to explore the houses and find any private things I could find. I especially liked it when it was the house of a girl my age or younger and I could poke through her things.
I remember once I was responsible for taking care of the neighbor's dog. They had a daughter about twelve-years-old, Kayla, and she was very attractive and very sweet, I had the hugest crush on her and I had such a great time searching through her room (I went over shortly after they had gone). I looked through her panties, I looked at pictures of her and her friends. I was really getting turned on. Then I found a small pile of dirty clothes in which she had a pair of panties which still had her smell on them. I smelled them while I jacked off, and then I grabbed a pair of her clean panties and jacked off with them on my cock, smelling her dirty panties. When I cummed I made sure to get some on her clean panties so that I would know she'd be walking around sometime with my cum rubbing on her pussy.
This other time I was house-sitting for a family that was friends of my family. They had a daughter, Ashley, about my age. I was poking through her stuff when I found some pictures of her and a couple of her friends in their bras and panties, very hot. Then I found some of her panties and jacked off with them like I had with Kayla's. Another day when I was over at the house I found her diary and I started reading it. Mostly it was boring stuff but I came across a couple of pages of sexual fantasies. I wasn't in any of them, but they were amazingly hot to read as a horny fifteen-year-old boy.