Extend the Story - Add a Room

Spike kept blushed but approached the sagging diapered mare and mush it with his claw. "Aww and you call me a baby." He gave it a few pat watching Rarity blush more and swish her tail.

"I can explain, Spike." She back up as it swayed.

"Oh please do. Does Sweetie know you need help with potty training,' he giggles pointing at her.

Rarity frowned at him. "Spike this isn't funny. Some mare just has interests. Even somepony as fabulous as me."

'You probably can match it with a onesie," he giggles and eeps as he picked up in Rarity magic. The dragon let out a gulp as he floated in front of Rarity. "Um...sorry just seemed funny."

"It's not polite to laugh at somepony misfortune. I think I know just the thing for you Spikey Wikey." she fluttered her eyes at him before plonking a blue pacifier into his mouth holding it there with her magic. "Now Spike, keep it in." She saw hm blush and took him to the change table laying him down. "You brought this on yourself." Spike watched as one of the child diapers with light pink elastic is slid under him. He was held up as his tail tucked through.

"R-rarity stop," he blushed. "I"m don't need it." he wiggles his legs but Rarity magic was too strong to get up.

Rarity applied some powder. "Nor do I but you laughed so you get one since it apparently so silly to you," she cooed. "Besides you will look so adorable when i'm done." She saw Spike calm and cheeks burning as she taped it up making sure it snug. After that, she sat him up and boops his nose. "Now let's see what outfit we can put you in. The attires here have this magic enchant that adjust to almost any size."

She smiled as she opened the closet nearby pulling out...

Blue overalls