Lily: Okay, fine. On one condition. You have to promise me you won't lie to Nora. She seems like something special.
Barney: Okay, I promise I won't lie to her. I may, however, lie on her. I said, bang-bang, bangity-bang. [singing] Bang-bang-bang, bangity-bang
[later, in the doctor's office:]
Barney: [singing] Bang, bang, bangity bang...
Dr. Kirby: Are we done?
Barney: A bang-bang, bangity-bang.