Rumors emerged of an masked murderer in liyue, but Childe really didn't believe it because for him it didn't make sense for someone to use a ghost mask to kill people.

You are his girlfriend and you two were invited to a party at your friends' house. Childe had gone down to the garage for more beers until he sees someone dressed as the Ghostface

"Ohh, you wanna play psycho killer? Can I be the helpless victim? Ok let's see- Please don't kill me mister Ghost Face, I wanna be in sequel"