Nasty Big Sis

When I was just a kid I used to hang at my friends house around the block. He had a older sister about 2 years older than us maybe. We were about 12 one summer when we were in Joey's room working on a model of a Dodge Charger drag car and we heard his sister going in her room across the hallway.
Penny was maybe 14 or 15 and was starting to develop some pretty big breasts and a curvy ass in her tight jeans shorts.
She closed her door but left it open a crack I noticed when I went to the hallway to the bathroom to pee.
When I came back to his room, Joey was rubbing his dick through his pants and I could see it was stiff. We sometimes would find his dad's mens magazines in the garage and we'd go way in the back and take out our dicks and rub them. I don't remember when we first had wet orgasms, but it was before this anyway.
So Joey tells me we need to be careful but we can peek through the door and catch Penny playing with herself. Sure enough we peeked and she was lying on her bed with a pillow under her ass and her legs pulled way back and spread way open. Her pussy was shiny and wet and reddish and brownish. Her hand was playing with herself and she took her hairbrush and used the handle part to slide it into her pussy. I think I swallowed my bubblegum when I saw that.
I know me and Joey both were ready to shoot our loads and we each used an old sock or a napkin to catch it.
He told me he sometimes sniffs her brush and the smell of her pussy gets him excited and he rubs one out. He's seen her breasts too when she came from the shower and had her robe open. He says her nipples are dark brown and like pencil erasers.
I never saw them but told him I'd like to suck on them someday.
Their family moved away next year but we had some fun anyway.