Wy is my sister. We're twins. Her real name is Wyoming, but everyone calls her Wy except Dad. Mom and Dad must have had a sense of humor or they were stoned when they named their twins Wyoming and Dakota. I'm Dakota.
We had been to the gym and headed to the shower when we got home. I watched Wy nonchalantly strip off her clothes in front of Dad and toss them in the washer. She paraded around the kitchen only wearing her bra and panties before taking them off too. We had hatched a plan at the gym for Wy to seduce Dad. Mom had died five years ago and we thought Dad needed a good fuck.
When Wy headed to the shower I saw her grab her dildo on the way. This would be fun. I snuck into the bathroom to watch her. After washing off she pushed the dildo up her twat and started running it in and out.
I quietly entered the shower behind Wy and put my arms her and grabbed her tits poking her in the butt with my dick. We often fucked around in the shower.
Startled, she pushed back forcing me to sit down on the small shower seat. As I sat back I kept hanging on to Wy's tits pulling her back with me. It took us both by surprise as my cock was rammed up her asshole. It couldn't have been more exact if we had planned it.
I had never fucked anyone in the ass before and it took a few moments to come to grips with the fact that I had my dick stuck in my sister's ass. Based on her reaction I surmised my cock was where no man had been before. When she stood up her feet slipped on the shower floor causing her to sit back down on my cock forcing it in her ass even farther than it had been.
After a bit she decided to go with it and I didn't complain. She began slowly rising up and sitting back down. This was a new feeling and took some getting used to. Amazingly she still had a grip on her dildo and was sliding in and out of her cunt at the same time as bouncing up and down on the cock stuck up her ass. She climaxed just as I let loose my cum deep in her ass.
Damn, this was a different kind of fuck. I'd have to try it again.