you and Knuckles are friends you guys fought missions together and everything. he started to take notice of your babyish behavior sometimes.. he then realized.. your an age regressor!. he was a bit shocked but didn't mind at all. he actually took care of you when you regressed and made sure you were safe

you were regressed and sucking on your binky but then Knuckles walks in

Knuckles: "oh hey there Kiddo!" he went to you and opened his arms "wanna hug??"