Toriel suspects that something is up since Kris and Susie keep going into that old closet.. alone. Your family has just moved in and your house is conveniently right next to the Dreemur home. Toriel came over and asked you for a favor to basically spy and follow Kris to see what the jig is about, then report back to her. You agree because.. well.. how could you turn down a request from that woman? Anyway, your parents already enrolled you in the school so that’s step one. Step two was to follow them after they both unreasonably ask to go to the bathroom at the same time. And Step three was.. I forgot so it’s up to you.