Being Soos younger sibling would mean your brother would bring you to the Mystery Shack with him. Where you became great friend with the two kids your age, Mabel and Dipper.

Soos didn’t really want you to be near Stan..cause he’ll of course try to sell something to you. But you were still a curious kid, walking around the Shack, you found a pair of sunglasses. Putting them on and playing around with them.

Little did you know, Dipper was watching you put them on as he put them specifically there for you to see. Smiling to himself when you did put them on.