Saturday night my sister gave me an amazing blow job and swallowed every drop of my cum. My mind was just a fog of ecstasy as I passed out in bed. Sunday morning I woke up and rolled out of bed around 10 with a hint of hangover. Got up and ate some breakfast which helped. As I went to go brush my teeth I realized the shower was on, and my sister had left the door wide open. At the time I was still in a bit of a fog, but I realized later that she was hoping I'd join, but alas, I just went to my room to wait for her to finish. Then I got up and showered. As I left the bathroom, wrapped in my towel, my sis passed by me and made a quick grab at my cock. "I'm coming for this again" she whispered as we passed. My cock twitched a bit as I turned into my room. My gf had texted that she'd be back in an hour, so I got dressed and got to work finishing up some homework. As soon as she got home I jumped her and absolutely fucked her brains out. My sister had gone out, so we fucked right in the living room for a good 30 minutes before we were both a sweaty panting mess. "I guess you missed me" she joked. "I always miss you baby" We got up and went about our afternoon after that. Before I knew it, the day was over and Amanda and I climbed into bed for the night. The rest of the week was pretty uneventful, until Friday. My gf and I decided to just hang out for the evening and my sis went to hang out with her friends for a bit. Around 10 we started making out in the kitchen and Amanda eventually dropped to her knees to start sucking me. I was leaning against the counter when the door opened. From the door my sis could see me over the counter but not my gf on her knees. We said hi to each other and my gf froze with my cock in her mouth. She was looking at me, looking for a signal of whether she needed to hide. My sis quickly went to the bathroom and I had my gf stand up and I hiked her dress up enough, turned her around and started fucking her from behind. I was fucking her slow when I heard the bathroom door open, so I stopped and just wrapped my arms around her. My sis came back to the living room "oh hi Amanda! I didn't know you were here" "hi! How was your night with the girls" she responded rather calmly. "oh good, nothing crazy" The whole time I'm just eye fucking my sis while inside my gf, and I think she got the message. "well I'm going to head to bed, I'll see you guys tomorrow" she said as she headed to her room. "Omg, that was so close" my gf gasped as she pushed me back and out of her. "let's go to bed so she doesn't catch us" We ran to my room and I of course left the door cracked and proceeded to fuck like crazy. It didn't take long for my sister to start peaking again, and I made sure to put on a good show for her. Saturday morning my gf had to work early so we passed out quickly. The next thing I know, there is a warm, wet mouth around my half hard cock. "you need to get to work don't you baby?" I muttered before fully opening my eyes. "she already left" my sister responded. My eyes snapped open to see my sister licking and sucking every inch of my growing cock. "I can taste her on you. She tastes good" "I know she does, but what are you doing?" "what's it look like? I told you I was coming for more. Now are you going to fuck me this time?" "no, I'm not going to fuck you" "oh come on, just like you fucked Amanda last night." "You're lucky I haven't already thrown you off of me" "Oh bull shit. You like when your sister sucks you big cock" she picked up her tempo and began sucking me hard. "fine at least cum for me then" It didn't take long before I was ready. "I'm gonna cum" She pulled it out of her mouth and stroked it hard and fast as a came on her tongue and face, and all over my stomach. "If you're not going to fuck me, I'm not cleaning you up this time" she said as she gave me one last suck and left the room.