Barney: Alan Alda. It was Alan Alda.
Lily: You never gonna believe what just happened.
[flashback to two minutes earlier:]
Barney: Who was that, um, guy from M*A*S*H? The main guy. What... Hawkeye from M*A*S*H. How can I be blanking on this?
Lily: Alan Alda?
Barney: No.
[Barney stands up and goes away. A woman approaches Lily.]
Woman: Hey, a word of advice? That guy you were talking to, Barney Stinson... I know he seems charming, but he's just saying whatever it takes to get in your pants. Sleeping with Barney was the biggest mistake of my life.
[present:]
Barney: Oh, my God. Where is she?
Lily: Oh, she must have left. She...
Barney: Well, she-she said I hooked up with her? What was her name? What did she look like?
Lily: She didn't say her name, but she had blonde hair, boobs. Kind of trashy.
Barney: Dead in the eyes with an aura of self-loathing and despair?
Lily: Yes!
Barney: That's all of them. Okay. Stay calm. Let's think this through. One of the girls who I lied to, seduced and abandoned is trying to ruin my life. Shouldn't be too hard to figure out which one it is. [starts working through all the women he's dated] Oh, dear God!