Damn, Maxi! Your 27 and your sis is 31?!?!
It sounded like your sister was 15, and you were 20.
If that's true then why would she lie? I can understand to a point the motivation about lying if you were young and were trying to hide the truth from your parents, but she's a grown ass woman.
BTW, you ever figure out what really happened? Was it just a terrible joke, or was it to cover up something?