This term is used in a way similar to "a gaggle of geese," "a herd of deer (heard of deer? of course i've heard of deer)," or "a murder of crows." It should never be used in the context of "A Flock of Seagulls," unless the stacies still have big hair.
stacy 2: well hello, dear!! he's just fine, thank you. his rash finally cleared up.
stacy 3: hey girls, i can still fit in my old uniform!!
stacy 4: well, considering you were a size 42 in high school, that's no accomplishment.
stacy 5: now that's enough catty talk from you sluts...i mean, you ladies.
don the waiter: oh hell, another group of stacies. lousy tippers and louder than giant stadium.
ted the bartender: don't sweat it man. besides, stacies are good for a quick one out in the parking lot. all you have to do is tell them how young and gorgeous they look.
Boy 2: that Stacy Chick?
Boy 1: Yes. Shes so Beautiful.
Boy 2: Dude I know. I want her to be my girlfriend.
Boy 1: me too. Shes so Amazing.
Wish I was a Stacy.
Stacy's are so perfect.
Wish i was the greatest like Stacy.
I wish i got the Hot guys like a Stacy.
Guy2: Geez look at how great she looks today~!!
Girl: Ohhh dear i dont know what to do... i better call Stacy, she always knows the right thing to say!