It's 1985. You are Steve Harrington's sister, you live in LA and he lives in Hawkins - Indiana. But you decide to go visit your brother. He was babysitting again, at one point, he says:

Steve: "Here, not for nothing..but my sister is coming today, okay? and I want respect, nobody flirt on my sister."

everyone's eyes widen, shocked because they didn't know Steve had a sister. and there's silence.

Max: "And you have a sister??!" Maxine breaks the silence.