Found it!
[quote]
(Cut to: Dr. Lance Sweets' office at the FBI building. He's having a session with Booth and Brennan.)
SWEETS: (He opens the blinds on his office window and walks back to sit down in his chair.) It's quite simple. Whatever Agent Booth says, you respond with whatever word or phrase pops into your head. And vice versa.
BRENNAN: Well that's ridiculous. I can't properly respond without careful thought.
BOOTH: Can't we just make it a drinking game?
SWEETS: No. This is a valuable, psychological tool, Agent Booth. When you respond viscerally we can get to the root of your emotional issues and figure out what binds you two together as partners.
BOOTH: Donuts.
SWEETS: Beg your pardon?
BOOTH: Donuts. Glazed donuts. I see 'em right there.
BRENNAN: Because you had no breakfast. You're hungry.
BOOTH: I'm starving.
BRENNAN: Yeah.
SWEETS: No, that's not the proper response.
BRENNAN: Of course it is, I'm explaining why he said "donuts".
SWEETS: The point of the exercise is not to explain, but to respond. Okay? Children can do this.
BRENNAN: Because it's childish.
SWEETS: Can we just try it, please?
BOOTH: All right, okay, fine, here we go. Are you ready? Hunger.
BRENNAN: Sex.
BOOTH: Whoa.
BRENNAN: Horse.
BOOTH: Cowboy.
BRENNAN: Child.
BOOTH: Baby.
BRENNAN: Booth.
BOOTH: What, what do you think I'm a baby?
BRENNAN: You're a father.
BOOTH: Oh. Mother.
BRENNAN: Birth.
BOOTH: Happy.
BRENNAN: Sperm.
BOOTH: Sperm? Isn't this getting a little weird?
SWEETS: No, keep going.
BOOTH: Okay. Egg.
BRENNAN: I want a baby.
BOOTH: Whoa.
BRENNAN: Horse.
BOOTH: Wait. Whoa, whoa, wait a minute.
SWEETS: Yeah, we can stop here.
BRENNAN: I actually found that quite interesting.
BOOTH: You want to have a baby?
BRENNAN: Yes, I do. I just—I just realized it. I should have a progeny. It's selfish of me not to.
BOOTH: Selfish?
BRENNAN: Yes.
BOOTH: Don't you need a, you know, guy to…
BRENNAN: Just sperm. You'd be a very good donor, potentially.
BOOTH: Me?
BRENNAN: But you need to be tested, of course. (Booth's cell phone starts ringing.) What, is something wrong?
BOOTH: Yeah. Okay. You don't just go around asking for people's sperm. (He answers the phone and talks into it.) Yeah? No, I wasn't talking to you. Uh, right. Yeah, okay. On our way. (To Brennan.) We got a case.[/quote]
Oh I need to watch this epi again! *sigh*