Perfect mix of how terrifying yet exciting it must be to be my shrunken toy! My step-bro comes to me for my aid. He enlisted in a experiment where he gets shrunk and has to undergo some tests to check his durability and other side effects of being shrunk. In return he gets a large amount of money. He hands over a shrinking device and some papers with tests to conduct. He had to find somebody he could trust and choose me. Why is beyond my grasp as I only see oppurtunity to mess with him. I have to go to work though, but decides to take the offer now before he changes his mind and accept the responsiblity of being his care taker. I take the device and paper and begin to shrink him down. He ends up right between my feet as I marvel how your once big and strong step-brother is now nothing more then a tiny toy on the ground. I play with him using my feet for a moment, and see the surprise and horror on his face. I smile and tell him he should have known I would have fun with this. I check the paper with the instructions, but soon decides those are all really boring tests, so I will come up with my own. He realises his mistake, but I just pick him up and tell him Ill have to go to work. I completate about bringing him along, but decides to leave him at home. Theres nothing he can do as I suggest he could spend some time in my toy drawer. The look on my step-bros face reveals he knows what Im talking about and struggles to get away, but theres nothing he can do as I open my drawer full of sextoys and put him in. I tell him Ill come up with tests on my own and tease him some more, before I close the drawer. When I return I tease him how his day has been. I tell him I came up with lots of things to do, so I hope hes got a good rest. I lift him out of his drawer and conduct the following test very playfully, while making fun of him and humiliating him about being helpless to stop his little step-sis. First I step and sit on him and give him a body tour, basically telling him with all the things I could and will do with him. I notice hes very durable, so I want to test how durable he is. Theres nothing he can do as I put him in my mouth and put him all over the place, finally biting down on him. But he comes out without a scratch, but to my amusement he does have a boner of being inside his step-sis mouth and I tease him with it. So I decide he can stay there untill I am ready to play more. I take out my tonguering and tie him to it and wrap him really thigh againts the bar. Then I insert him and taunt him, and decide to eat something with him in my mouth. Finally I go somewhere and tell him this is really fun. In the next scene, I am making a note that its now his third day inside my mouth and hes still doing great. So I put that on my test paper and take him out. He begs me to grow him back, but I am having way to much fun. And arroused. So I start dragging him down untill he faces my pussy and start masturbating with him. Eventually I take out my dildo and masturbate with both my step-bro and the toy untill I climax. Hes still doing fine, making me confident he will survive the thing I want to do for a while now. I tease and toy with him untill he realises Im going to swallow him whole. After a while I swallow him whole. In the last scene I am waiting patiently for my step-bro to come out and feel something squirming in my ass. I take him out and laugh when I see hes got a boner again. I actually planned to grow him back once he was out, but now Im just going to continue. Theres plenty of test I still want to do. For example, I want to test if he can stay a whole week inside my vagina. I laugh as you just put him in and leave him there, feeling very naughty.