Phineas and Ferb, Season 3

Lawrence:
Hello lads!

Phineas:
Hi Dad!

Lawrence:
What are you boys doing?

Phineas:
I was just telling Buford about phone booths.

Buford:
And I'm not buying it!

Lawrence:
Oh no Buford, they were real. They were tiny rooms where you could talk on the phone in private.

Phineas:
Yeah! And you'd have to put coins in them to make calls.

Buford:
You guys are blowing my mind!

Lawrence:
Speaking of coins... What's this here? Behind your ear? [Reaches behind Phineas's ear] It's a quarter!

Buford:
How did you do that?

Lawrence:
A magician never reveals his secrets. [Walks away]

Buford:
Your dad's really great at tricks!

Phineas:
Not really, I just keep a bunch of quarters behind my ear 'cause he enjoys it so much. [Pulls a handful of quarters from behind his ear]