Will uses his and Nico's dates as methods to blackmail Nico into actually, y'know, functioning as a healthy human being.
Nico: hey, want to watch this anime together?
Will: then you'd better eat something other than cereal bars and coffee. I know you're the ghost king and all but it's like living with an actual zombie.
Nico: I really want to kiss you right now
Will: drink another cup of water and I'll think about it
Nico: Will, the love of my life, will you marry me-
Will: not until you have an actual sleep schedule. But actually yes Nico I love you