The heat is picking up this summer and my and my wifes fantasies are running over the top. We have always enjoyed playing out fantasies while having sex and my wife has decided to give me the hottest fantasy ever. My wife is georgous and her sister two years younger is just as hot. In fact they look very much alike and I have often got in trouble in the past when her sister has stayed over, patting her on her ass thinking it was my wife..........oh at least it sounded good after I apoligized. I have always shared my fantasy with my wife about having both of them in my room, lights out, tie my hands to the bed post and blind fold me with a silk scarf and then one or both of them have sex with me without my ever knowing who was riding my cock. I told her that I think I would be able to tell who I was inside with my cock and if they came loud, I would be able to tell their voice. They do however even sound alot alike. My sister in law is coming into town in three weeks, she is single and my wife shares their conversations with me and tells me how horney her sister is all the time. She is a nurse and works long hours and occassionaly has a fleeting moment in a back room with a doctor before the next surgery. My wife has told me that she has joked with her sister about my fantasy in the past and recently, and her sister has laughed about the possibilites with my wife. My wife and I have put this fantasy together: We'll have a couple of cocktails thru out the evening then I will go upstairs to my bedroom where I will strip naked and wait on top of the covers. My wife will come upstairs and try my hands to the bedpost and place a scarf arounf my eyes so I can't see. She will then go back down the stairs and close the door. A short time late I will hear the door open and either her or her sister will undress and get on top of me and fuck my brains out. She will then leave and close the door behind her. A few minutes later the door will open and the same scenario. Either it will be my wife both times or her sister and my wife or her sister both time. I will never know.............or so they say because she feels like I will not be able to tell the difference of whose fucknig me. Afterwards she will come up and untie me and it is agreed that we will never discuss this again. I'll go downstairs, have a few more cocktails with them, talk and go to bed. I can't waiting. Counting the hours.