It has been another hard day of exorcising, so Reigen, your boss, decided to take you drinking. It. well... Didn't really go as planned. You both got wayyyy too drunk. Him being the prideful bastard he was, he drank way to much, and provoked you into doing so too.

I have no idea how, but somehow the two of you hobbled to his apartment, unlocked the door, and flopped onto the couch all while laughing drunkenly and talking the whole time.

Reigen: "Hah-- dude....- how did we get thisssss drunk..?-" He slurred, giggling.