Krista was always modest and a conservative. She never even wore bikini, so I was confused about why she had left the door open. I fixed me a glass of...water and drank it down. Then headed back to my room. I was at a conflict with myself. One part of me wanted to look in and see my sister naked, the other part of me knew it was wrong. As I approached, the good side me was winning. I made it half way passed the door, and then….“Kris, hey can you get me a towel?”I stopped dead in my tracks. I. . . in a short session.I pulled her to bed.. she managed to empty the beer mug in between.In bed, She managed to push me on the bed started kissing, kissing my nipples wildly running her hand over my Bermuda… stiffening my cock to paining level. I could not control.So managed to push her hand away and removed my Bermuda . . . I was stark fully…She attacked my nipples again, my belly and cock with her hands for a while.I: I can’t hold, please fuck me or I will fuck you…V: Today, I will….Telling. “In your cunt?” I shoved my finger into her pussy, bringing a soft moan from her lips. “Or your ass?” I pulled my sticky finger out and shoved it up her ass. “Oh, Master, I don't care!” she moaned. “I only care that my slutty body makes you happy.” “Good girl,” I answered, standing up and giving her ass a pat. My cock was hard and I rubbed it against her puckered asshole and shoved it in. Lillian gasped in pain and smiled back at me. “Oh, fuck my slutty ass as hard as you want, Master!” she. Then mom reached for my hard cock and placed it right at the entrance to her pussy. I pushed my cock into her and mom smiled up at me. As I slipped my cock in and out of her she told me how good it felt in her. Not only was it her first ‘second fuck’ in many years but my cock was bigger than my father’s cock was. Plus the fact that this time the second fuck was incestuous. It had been many years since her father had fucked her and she hadn’t realized just how much she had missed the incest.