Why does quagmire keep saying gigity gigity gigity goo?

Answer 1

The expression "giggity" (or giggety) is one of sexual excitement. He may say giggity giggity or Great Giggity Goo. This is the equivalent of "oh, boy" or "woo hoo."

Seth MacFarlane explained where the phrase came from:

A friend of mine who is a stand up comed[ian], by the name of Steve Marmel, used to call me and do this Jerry Lewis impression and do the geshmoigan, geflavin and all that business. Then I would do the same back to him, and over the course of several phone conversations it devolved into this giggity giggity giggity, this kind of lazy Jerry Lewis sort of thing.

Answer 2

he is sexually aroused thus saying gigity gigity goo o right lmfao im a genious

Answer 3

Quagmire says "Giggity" when he is sexually aroused. Other forms of "Giggity" are "Giggity Giggity Goo!" or "Giggity Giggity Goo, ooh ah!".