This isn't looking good: You've awoken on a strange world, and the first person you meet shrinks you, albeit by accident. The situation couldn't get any worse - or could it? While you were sitting on the (now huge for you) chair pondering this, Rosa decided to relax from the spell training, thinking she failed because she was kinda tense, and sit down on the chair. YOUR chair. The one you were sitting on.

Since this was an early hour (good for tranining alone, you see), Rosa wasn't wearing much clothing - just a small battle bustier that looked a bit like a green-ish one piece swimsuit and had a very small behind, like a thong. You only realized this, of course, because her butt was now above you. Her backside wasn't small for her size, so now it looked gigantic to you. She started sitting down, her ass getting closer and closer. You freaked out and fell on your back, and hastily lifted your arms (As if that was going to hep any) and tried to yell "Wait!"

But it was useless, and her rear end placed itself on the chair, squishing you under it. Fortunately, the chair had a Protes spell attached to it, which went to you and allowed you to withstand her weight just fine. Well, "just fine" was an exaggeration, she was still heavy, but your life wasn't at risk here.

Rosa giggled "This chair tickles!" and started wiggling her butt back and front, liking the strange feeling the chair caused on her "Must be the Protes spell from before. Didn't know it had this wonderful side-effect!". Actually, it was you, but she didn't know that. You did, of course, because she was grinding her buttocks on you, which hurt more than just the sitting, making you wish she'd stop. Admittedly, she had a fine ass, but right now you weren't in "position" to enjoy it.

"Well, I think I feel better now. I should continue my magical practice." And saying that, she got up. After all the grinding, you were...