This is after the monsters got out of the underground, they live their lives up on earth, doing normal things. Except Alphys, she's weird as all Hell

You walk around, since it was December, it's snowing a lot today and every one was outside, having a Snowball war. Papyrus shouting something about bones, Sans shouting "Wheeyyyy" or something, Undyne going "nyaa" and so on and so forth

Genderless Child: "Gonna be honest mate, I am not liking our odds here. We've got Alphys, we're so dead"

Sans: "Listen, mate! Ya just gotta keep firing! Like I do to your mum WHEYYYYY GET REKT!!!"

Sans chucks a Snowball at Papyrus

Papyrus: "YOU'RE ABOUT TO GET BONED BY MY SUPER AWESOME SNOWBALL!"

Toriel: "SNAILS!"