"Grandpa has errands to run today sweetie. And the only way you can join me is if you be a super big boy the whole time" Rick stated. He stuck a pacifier in the boys mouth.

Morty whimpered in small protest. He hadnt even gotten to be a baby for a whole day yet. Morty latched onto the pacifier with the big rubber bulb filling his mouth. "No wanna be bigs." He sniffled. There was no doubt he would make a big stinky as well from all the laxatives. There was no way he could stay home alone as a baby.

"Well then looks like we're stuck here, stinker" Rick replied. He placed Morty in the playpen and put some learning cartoons on. Rick sat back and watched his baby.

He didn't mind staying but he felt a bit bad for not letting his Grandpa go on his errands. He sat in his play pen and looked back up at Rick. "Sowwy." He lisped hoping he didn't make the man mad. He turned back to his toys starting to play a bit. A good hour later he let out a grunt. He made a stinky in his diaper but didn't seem to even notice as he continued playing.

Rick smiled ss he watched Morty play. He chuckled as Morty filled his diaper without noticing. "Someone made a stinky!" He says. He began to read a book as Morty played.

Morty blushed a lot when Rick pointed out his diaper was stinky. The infants cock still being hard from his morning wood. He still wouldn't touch but he no doubt wanting to cum lots and lots. He didnt seem to mind his tinky diaper and kept playing with more baby noises leaving his mouth.

Rick smiled and pet Mortys head gently. "Baby where do your cummies go?" He asked. He groped and mushed Mortys diaper roughly.

Morty made a needy noise feeling Rick's rough hand grope him. It felt so very nice. "Diapee gwandpa." He cooed back. His diaper was the only place he ever wanted to cum in the first place now. Morty belonged in diapers forever and he definitely wanted that.

Rick smirked and began to laugh. "I wonder if i can train you to mess on command..." He said. "That would be fun to try on one of our adventures~" He teased.

If Rick wanted to try that idea than Morty would be pretty helpless to stop him. He would be messing himself randomly anyway having pretty much no control of his bodily functions. He was just a baby for Rick to do as he wished.