I think i might be in love with my sister?

okay so one of my friends was showin me s of this smokin hot girl, and i started to them... then he gave me the girls number and we started talkin and i really started to like her, like a lot, so i told her we should meet up at the movies or somethin like around back. so i'm standin around the back of the theater for a couple mins and then my SISTER walks around the corner... it was so akward and embering, idk what to do, we both knew what was goin on and i tried to pretend like nothin happened.... but i mean i really really liked her.... what do i do? should i go for it?