Alya takes them both out on a walk.

"Adrien, Marinette, I was thinking about taking this little party out on the road."

"B-But... Dadd--um, Father said I shouldn't go out when I'm like this," said Adrien, tugging the hem of his shirt down further.

"Don't worry little boy, I've thought of everything."

Alya set down her diaper-bag and reached into it, pulling out a set of clothes.

Alya squeed at her handywork. She had put Adrien in a loose, full-bodied onsie. The whole thing covered him from head to toe, was mostly black with white patches and an aesthetic set of animal-ears. It made him look like a big tuxedo cat, with a pair of purely aesthetic glasses and a pacifier to obscure his face.

Gabriel and Natalie had forbidden Adrien from leaving the mansion while he was in his headspace, not only to protect him while he was at his most ****, but because they were still working out how to reveal that the heir and face of the Agreste-brand was also a little.

Alya decided that Little-Adrien shouldn't be cooped up in his house his whole life and he needed proper socializing, so she would disguise him in a number of ways so that no one would recognize him. That and it was an excuse to dress him up in adorable outfits.