Crazed Sister Impregnation Fantasy

I ask my brother to impregnate me… he says no! I don’t know why… I’m not asking for him to be the dad! I just want him to give me his seed while I’m ovulating… I decide its up to me…. Over the next few days I go into my brothers room while he’s gone and I collect his filled up, used condoms… saving them for my peak ovulation day! Then I use them all to fuck myself… fantasizing about fucking him while I fill myself with his cum over and over again…