The next morning we woke up and mom took a shower while I made something to eat. I was off on a 3 day business trip with my job, and I spent the morning packing. Mom and I said very little to each other, probably because neither of us knew quite how the other was feeling about the whole situation. I kissed mom on the cheek and headed off, with the image of her standing in the doorway in her oversized t-shirt in my mind.
The next three days were hell. I could not stop thinking about mom and how good it felt shoving my thick meat into her wet hole. Or how good it made her feel when I sucked and blew on her erect nipples. When the trip was finally over, I was excited to be coming home to mom, and looked forward to continuing what we had started. I got in really late on Thursday night, and opted for bed without bothering my mother. Friday morning I arose after about four hours of sleep to go to the bathroom, not bothering to throw on my shorts as I was the only one downstairs. Oh yeah, and also because my mom had already seen my thick penis as it slammed into her only days earlier.
As I approached the door half asleep, I saw the light already on in the bathroom, and mom's image reflecting in the mirror. I had no clue why she would be down here in my bathroom, but I lost any thought process when I saw that sexy ass wiggling around in there. Her dark hair was up in a pony-tail which also seemed a little strange as mom never has it like that. The sight of her tight delicious ass immediately brought me and my cock to life, and I decided to surprise mom by catching her off guard. I ducked down so she wouldn't see me in the mirror and I closed in on her slowly and quietly. My dick was now leading the way as I got to the door. Mom had on just a nightie, and she seemed oblivious to my approach. I was now right behind her crouched down, and I moved in for my prize.
I stuck my tongue out and licked her sexy asscheek as I pulled her closer to me. Now I expected her to possibly be a little startled by my touch, but she let out a yelp that woke the neighborhood. She whipped around, knocking me to the floor, and there she was, my sister Kim with a "what the fuck was that?" look on her face.
Yeah, apparently my twenty year old sister had come home for the weekend, and now that I think about it, I did remember she was supposed to be home this weekend. She stared me down, my hard cock dangling in front of me, stiff as a board because I thought I was about to get laid. In my defense, Kim is the spitting image of my mother, with the exception of a larger chest and slightly plumper ass. People often mistake them for sisters, so my mistake was somewhat understandable. Staring back at her, I couldn't help but devour her body with my eyes. She wore a blue nightie, her huge tits almost flopping out in the open, with a gorgeous ass exposed.
"What the fuck are you doing?", she screamed at me.
"I'm sorry Kim, I didn't know you were home, I thought you were mom"
