Marty McFly: Yeah, well, you shouldn't drink.
Lorraine Baines: Why not?
Marty McFly: Because you… You might regret it later in life.
Lorraine Baines: Marty, don't be such a square. Everybody who's anybody drinks.
[Marty takes a sip from Lorraine’s bottle then spit-takes as he notices Lorraine lightilng a cigarette]
Marty McFly: [nauseatingly] Jeez! You smoke, too?
Lorraine Baines: Marty, you're beginning to sound just like my mother.
Back to the Future quotes