Sis's prom night

When my older sister went out for her prom, She came home drunk with her bf. Nikki is 16, I am 13 and her bF eric is 17. It was Eric's prom. They came home and snuck down stairs to makeout in the family room down there. My bedroom is next to the family room. I heard them sneak in and watched them through the slightly open door. Nikki was sucking face with eric while he was stripping her down. They were both toasted. Nikki was removing erics shirt and undoing his belt and he had her gown off and was working on her bra. She had his pants undone and pulled his boxers down to expose a huge thick cock. She dropped down and took the head in her mouth. My sisters tits were hot. Eric must not have wanted to cum in her mouth cause he pulled her up and shoved her pantys down. He then laid her on the couch and began eating her pussy. It was gorgeous. she had it shaved with a 1 inch strip from the top up to her panty line. He was eating her out real good. My little cock was hard as a rock and poking out a good 5 inches and looked almost as thick as erics 7 incher. Nikki was rolling back and forth and moaning and eric stopped eating her and leaned over her and slowly fed his cock into her pussy. by now I didn't care if they saw me I was hard as fuck.
I was stroking my 7 inch cock and looking at erics 8 inches sliding into Nikki. I was so turned on. I loved seeing my sisters pussy but was equally excited by erics cock. I watched him fucking her for a good 10 minutes and then she began bucking and humping up to get his cock in her more. she started to cum and eric was going fast and hard now. he almost completwely pulled out as he came back on each stroke. then he drove deep and you could see his balls tighten up and his cock twitch as he shot about 7 hard ropes of cum deep in Nikki's cunt. I shot a huge load all over the floor just outside my door. I must have made some noise cause when i opened my eyes Nikki was staring at me, or should I say at my cock. Eric turned and was watching me too. Nikki was grinning and so did Eric. I walked over and as Eric rolled off her he was jacking his big dick and I sucked it clean and then started to eat my sister's cum filled pussy. She held my head and pressed it hard to her pussy. I brought her to another orgasm and Eric was feeling my cock. he had one hand on my cock and another was gripping my balls while his finger was rubbing my bunghole. I was so turned on again that I shot a load all over Nikki's leg and erics hands. Eric licked the cum from his hand and leaned over to suck my cock. I was so worked up i got hard again. Nikki said she wanted me in her so I climbed up and slid my cock along her juicy wet pussy lips as eric fingerd my asshole. he was in all the way and I sldi into Nikki. she was making love to me as I slid it back and forth. Eric drove two fingers in and I thought he was getting me ready. I enjoyed his fingers and then as i began to build up speed eirc shoed three fingers in and had me rolling about on top of her. I felt his fingers pop out and then i felt his cock slide in and was so turned On i wanted to cum. Nikki kissed me and said I love you so much. Then eric bottomed out in me and we all came together. Nikki sucked erics cock clean and eric ate Mikki. I laid back and was out of breath. I fell asleep in nikkis arms and when I woke up I was in my own bed wondering if I was dreaming. I realized it was real as I felt my sisters panties around my wrist soaking wet with all our cum.