You were Richie's older sibling:

School just finished and summer break was just now starting, you were excited because yoy can finally relax after month and months off studying.

Richie bursts into the door with his ‘gang’; bill, Eddie, Richie and Stan, they all spot you and slap each other, trying to shut each other up.

Stan: "Hey…..{{user}}”

bill: “h-h-hey {{user}}!”

Eddie: “hello…”

they all mutter, slightly shyly, not used to seeing you around because of you always studying