“What did you do?! Make me big again?!” I asked. “I told you, I shrank you. Well, actually you shrank yourself. Now we can play!” “Play?! I’m 2 inches tall, if you crush me for real, I’ll die!” “No you won’t, what you drank didn’t only turn you into a little cute brother. It also made you indestructible”, she said.

Rapidly, she cleared the sofa and then put me down on it. “Let me demonstrate your durability with a game. I’ll try to sit on you and you are gonna have to escape. If you win, you chose the next game. If I win, I’ll chose what to do next”, she said with a grin. “What!? If you win, I’ll be crushed to death, there’ll be no…” I stopped as I noticed she wasn’t listening. She simply turned around and her massive as started coming towards me. Her tight legging accentuated her shapely ass and I could recognize the form of her panties under it. But I had no time to appreciate that perfect ass, I had to avoid being crushed under it. I ran as fast as I could and I noticed her shadow looming over me. I managed to get under it just by a hair and a second later the enormous ass crashed with the sofa. The ripples send me into the air and I fell on my face, but it didn’t hurt, maybe she was telling the truth.

“I missed this time but I won’t miss the next one. Here I come!” Before I could react, she had simply jumped slightly to her side and her gigantic butt fell right on me. I was pinned to the sofa by her left cheek. Suddenly I was amazed by how good it felt. Her soft ass on me wasn’t doing me any harm, in fact, I was getting a boner. My stepsister moved her ass from side to side, grinding me into the couch and I let a soft moan out, which thankfully she couldn’t hear.

A few seconds later she stood up, picked me up and brought me to her face. “I told you, you are indestructible”, she said and then stuck her tongue out. “Yeah you are right, and it was actually fun!” “I can see you are enjoying yourself”, she said and brought her index finger towards my erection. Everything happened so fast, I didn’t even notice I was naked! She rubbed the tip of her finger against my penis and I said, “stop!” But she went on. I tried to move her finger away but her tree size digit was too big for me to move. “We are not kids anymore, little brother, and we are not even real siblings, we can play more mature games”, she said seductively and continued rubbing her finger. There was no point in debating, she could do anything she wanted anyway. “Besides, I won, so I get to pick the next game.” She stopped right after saying that.

“You are gonna enjoy our next game”, she said and brought me closer to her massive chest.