cum crazed step-sister - impregnation fantasy

I ask my step-brother to impregnate me... he says no! I don't know why... I'm not asking for him to be the step-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 step-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...