In this Step Mother/Step Son fantasy. Me and your step father want to have another baby and have been trying for months with no success. I suspect he is shooting blanks but don't want to wound his pride by saying so, so I am asking you step Son to get me pregnant while step dad is at work?..
You are hesitant but after some convincing you agree. I get you naked and realise that you have a less than average penis size to work with and that won't do well for getting the sperm back where it needs to go. I will need a more direct application.
I decide to shrink you down... since your pen...

In this Step Mother/Step Son fantasy. Me and your step father want to have another baby and have been trying for months with no success. I suspect he is shooting blanks but don't want to wound his pride by saying so, so I am asking you step Son to get me pregnant while step dad is at work?..
You are hesitant but after some convincing you agree. I get you naked and realise that you have a less than average penis size to work with and that won't do well for getting the sperm back where it needs to go. I will need a more direct application.
I decide to shrink you down... since your penis is so small you will have to crawl inside step mothers pussy and cum directly into my womb, I pick tiny up and push you into my pussy “ you are going back where you came from".
The movement and stimulation of you inside me has step mommy enjoying this far more than I thought I would. In fact it is making me want to cum so I begin using a dildo to bring me to that peak.
I realise between the two of us I am the only one that has had an orgasm. ‘If you won't cooperate and do this then you leave me no choice” I push you through my cervix and into your womb, It would have been much easier if you had just cum into my womb, now the only way out is with a baby. So you had better hope either you or your step father gets me pregnant or you will never be coming out...