You were caught off-guard both by how you couldn't stand and by how thick your 'underwear' felt. You weren't sure how you didn't notice either for a minute, but it made the swap feel even heavier. Try as you might, you just couldn't stand up on two legs, the realization that you didn't even have the responsibility - and probably even the skills - to use a toilet crept up on you as you looked inside of your pants to see a diaper, all the while James' giggling mocked you.
"Michael no walk!" James enthusiastically said as, despite previously not being able to, he got up and walked like a natural and brought his toy blocks over as you just sat down, defeated and fascinated, but given the remote's power you could probably just swap those back. Just those traits, like you wanted to be treated like a baby. And yet, a strange fascination made you want to stay in this infantilizing position.
"Looks like I can't," you said as James started playing with the blocks. You weren't particularly interested, but you humored him by toying around with them, holding one in your hand and contemplating it. With just one swap, you'd given your baby brother the responsibilities of an almost-adult, and the skills to go with them, and now you were being looked after by him all because of this remote - that you quickly sneaked into your pocket before anybody noticed it. Looking at James in your nervousness, though, he'd quickly made a stack almost as tall as he was, giggling all the way! You were pretty sure he wasn't able to stack that many blocks before.
"Michael, fall!"
"Fall?"
"Blocks fall!"
"You want me to make the blocks fall?"
"Yes!" You then touched the tower, and all of the blocks James had stacked fell over, making him laugh. Continuing your thought, on the times you'd tried playing with James you usually just watched him do his thing and sometimes helped out... only now he was meant to be looking after you, but didn't seem to get the picture you weren't interested in what he was, so there were limits to how much maturity got swapped to accommodate the responsibilities - you still had the superior speech. "Happy blocks?" he diligently asked. Well, with your 'responsibility', you could afford some honesty.
"I'm not really interested in blocks, can we go to my room?" you asked, thinking it would probably have things that interested you, though given your current state you were curious if - or how - it changed.
"Tidy!" he said undeterred before responsibly tidying up the blocks. He did seem to take that criticism well... but if you didn't have the responsibility to move through the house freely and you were 17 and he was 1, how would he take you there with his tiny body? After the blocks were tidied up, he then started walking towards you. "Michael room! Michael room!"