>Papyrus is the Knight
>Papyrus will be a secret boss
Enough. The true and only likely answer, is that Papyrus will be your date at the Festival.
>hanging out with him has been teased since chapter 1
>Sans doesn't want you hanging out alone in his house
>probably wants his brother to come out and socialize for once
>but Sans will be occupied with Toriel
I'm betting you'll be at the Festival with Susie and Noelle, but you're all saddled with Papyrus, and he just completely drags the mood down.