Heather and I had lived together in that tiny place for a little over a year. We enjoyed each others bodies that whole time. When we both got better jobs we decided to move to a larger place, but the larger places were two bedroom and much higher rent. We could afford a place by ourselves for about six months, so we got the place and looked for a roommate. We agreed on a nice woman and she moved in.
Heather and I never told her we were brother and sister, she just assumed we were married and we let her believe that, we figured no harm no foul.
Shortly after we moved in Simon, Heathers ex came over; I don't know how he found our address, but there he was. He wanted to talk to Heather. The last time he "talked" to her she ended up with a fat lip and swollen eye. I told him she was happy and he need to leave. Thankfully I was the only one home. He tried to push past me and started yelling for Heather. I explained that Heather wanted nothing to do with him, and I invited him to leave. He gave me a hard shove and got into the apartment. Somewhat more forcefully I invited him to leave again. In the process a chair got broken, we only had the couch and chair to sit in to watch tv. After we discussed him leaving for a short bit he left, I told him to never come back.
I cleaned up the blood and disarray before the girls got home. I didn't want Heather to get scared, and I didn't want Becky to get worried and move out, we couldn't afford it.
Heather and I never made it a secret we were in love and lust with each other. Becky would catch us sometimes kissing and feeling each other out. I love the way my sisters breast feel in my hand. I love the way she kisses, deeply and with lots of tongue.
Becky was the shy type, when we would watch tv she wouldn't pick anything. If we shared a dinner it was what we liked and she would just go along with it. Heather told me she kind of liked the way Becky acted. She wondered what she was like in bed, did she just lay there or scream? Did she like oral sex, both giving and receiving? While my sister isn't a screamer, she is kind of loud. She, as I, like oral sex, both giving and receiving. I asked her why she was thinking about Becky's sex life.
"Becky seems to be at home a lot and I haven't ever heard her talk about any guys, I'm just curious."
Heather was always open to another sex partner, female only she told me. I made sure she meant that the partner would join us, not just her.
The apartment had only one master bedroom with it's own bathroom. We took that room and Becky used the other room and the other bathroom. Sometimes we would catch her walking by our door and peeking in. We didn't leave the door open, but sometimes it would be open a crack. Sometimes we were fucking our brains out when she would walk by. Heather and I didn't mind, I was hoping she would join us, but she just kept walking by.
One day Becky was out for the day.
"Becky is gone and I need you right now!" Heather was insistent sometimes, and when she wanted sex it was right now.
We were in the living room and started kissing, I reached under her shirt and started massaging her breast. I felt her nipples get hard, so I lifted her shirt more and started sucking on them. I rolled them around my tongue and with my fingers. I reached under her dress and pulled her panties down and slid my finger into her wet pussy. She let out a moan and opened her legs a bit so I could get in there better.
She had reached down into my sweats and grabbed my cock. It was rock hard and she started stroking it. She leaned her head back a bit and I went to work on her nipples again.
All of the sudden she turned, pulled up her skirt and bent over the arm of the couch. I dropped my pants and underwear and got behind her. I started to push my cock into her pussy but she stopped me.
"I don't want it there, what I need right now is you in my ass." She said as she looked over her shoulder.
I have been using her ass for a while now. Both of us enjoyed it, I liked the rubber band feeling around my cock, and she liked the fullness she felt when I buried my cock deep in her butt. So I wasn't surprised when she said what she wanted. I grabbed the lube from the bathroom and put a bunch on the outside of her hole. Then I took a gloop of it and gently massaged her rosebud and pushed the lube inside. At first it was only one finger then I worked two then three fingers in.
