Malcolm in the Middle, Season 1

Hal:
Now, I want to tell you what happens when a boy really, really likes a girl. And Dewey, I'll make this easy for you to understand. [looks around for toys and grabs a robot and a girl doll]

Malcolm:
[to the camera] Oh, man! I still play with that.

Hal:
You see, there's a certain thing that happens between normal healthy people. It's called chemistry. [accidentally fires toy gun from the robot] Well, that doesn't happen, except maybe the first time. But what does happen is this. [imitates robot] "I like you!" [imitates girl doll] "I like you, too!" [back to normal voice] ... and if they love each other and take their proper precautions, they'll have sex, but I've told you that already.

Dewey:
[smiling] Not me.

Hal:
Well, ask your brothers.

[Malcolm & Reese give disgusted looks]

Hal:
If the boy is from our family, it goes a little more like this... "I like you." "I HATE you!" "Now, I LOVE you!" "LEAVE ME ALONE! Your insane neediness is driving me away!" "Look at me! Look at me, I'm crazy! Pay attention to me! I'm an idiot, watch me crash and burn! Woop-woop-woop, whoo!"