Quagmire: "GIGGITY GIGGITY?"
Quagmire: "How old are you?"
Cheerleader: "Uhh, sixteen."
Quagmire: "Eighteen? Alright"
Quagmire: "I like where this is going, GIGGITY GIGGITY, GIG, IT, EE."
Many people believe the term was coined by Quagmire from Family Guy, but it was in fact used by Breckin Meyer's character, Walter in the 1998 film, Can't Hardly Wait.
"i had sex with your girlfriend last night, giggity giggity!"
Guy: "Giggity giggity."
People: "Awe, man, you sick!"
Girl: Hey, look at that hottie!
Me: Giggity giggity.