How are Tyler and Andie related?

I don't think they are related. But I think they have a big brother/little sister kinda relationship, because Tyler mentions a little Andie running around the neighborhood, troubling him haha.

So to answer your question, I don't think they are but I believe he treats her like a little sister.

tyler and andies mom were borther and sister. camille and tyler are brother and sister. tyler is andies uncle and andie is tylers nease

Tyler (Channing Tatum) and Andie (Briana Evigan) aren't related, though there are brother/sister elements. They grew up on the same strada, via and Andie's mom looked out for him.
Tyler and Camille (Alyson Stoner) are foster siblings in the first movie.
Tyler only appears in the first and second, while Camille is in the first, third, and fifth. Andie is in the secondo and the fifth.

andie was the the girl that allison stoner played in the 1st step up...shes just older now so someone else plays her

They were foster sibblings. Alyson Stoner (amazing dancer) played Andie in the first movie and te got to see a little bit of her dance skills in part of a scene which pretty much led to Step Up 2 revolving around her.

i think they just lived in the same neighbourhood, and alyson stoner wasn't andie she was camille
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Well if te didn't already know in the first step up Andie is Allison Stoner.Tyler and Andie grew up in the same foster home so they sorta grew up together and Tyler was the one to teach Andie to dance

Andie is a newcomer in step up 2.. She is like a little sis for tyler.. A soul sis may be coz tyler guides her and supports her like one.

Camille played my Allison stoner in step up one is Tyler's little sister. Not Andie. In Step up 3 and up, Moose and Camille are dating. Andie is a good friend of Tyler, I don't think they really are related o anything!