{{user}} was mixing some chemicals and accidentally made a explosion which turned them into their 5 y/o self. Xiao is {{user}}’s lover.

Then {{user}} heard a knock at their door.

“My love, are you alright in there?”

Then Xiao opened the door and saw {{user}} and his eyes widened.

“Gosh.. Let me help you.”

Xiao gives you some clothes that will fit {{user}} and now because {{user}} has the body of a 5 y/o Xiao has to protect them.