My co-worker and I are currently exchanging such witticisms as “Your epidermis is showing,” followed by an email regarding whether her refrigerator was running, and a discussion involving whether it would be best to let Prince Albert out of his can.
Unfortunately, I’m now stumped. Can anyone else think of any other childish quips that I can use?
Have you gone through the “A sphincter says what?” routine yet?
Accuse her of masticating in public. Tell her you saw her in that play and you know she’s a thespian. You’re rubber and she’s glue.
If her nose runs and her feet smell she is built upside down?
A coupla oldies we never tire of where I work:
“I know you are but what am I?”
“You and what army?”
“You think you’re so cool…but you’re not!”
“Make me!”
“Takes one to know one…”
“The one up my sleevie”, and make a fist to wave around…
And another funny thing we do…whenever the question is “where’s the (insert name of just about anything here)”, and you just happen to have it, the correct response is:
"Why it’s…RIGHT BEHIND YOUR EAR!! (while making pathetically ham-fisted attempt to ‘magically’ produce it with a fluorish). Especially funny with large, bulky, or explosive/toxic materials (I work in a lab).
“Make me” is usually followed by
“I don’t make trash, I throw it out”
I suspect that if you looked closely, you might notice that her zipper is up.
My ex-bf, when I would ask him where something is, would always answer “if it was in your ass, you’d know where it was”. It used to frustrate me to no end, but ever since then when someone asks me where something is, I always think “If it was in your ass, you’d know where it was”
Here is one to do when you are at a friends house and the phone rings. As your friend (For this example, call her Kathy) goes to answer it, get her attention and say:
You: “Hey, Kathy”
Kathy: “What?”
You: “Your phone’s ringing. I’m just trying to be helpful.”
Then there is the one where when anyone says anything about being deaf, hard of hearing or having a lack of communication, you respond by saying, “What was that?”
How about the ever popular goose chases for such items as:
Tell her you can see her orbicular muscles (lips).
Asking girls if I could see their uvula often got interesting responses.
but did they stretch their lips wide open for you to see…?
As you’re walking by her, loudly exclaim as you point to the floor, “Hey <insert name>, you dropped your pocket!”
or
Tell her go dig half of a hole.
Tell her something she’s looking for is “under” then mumble. She’ll say “under where?”
And you can say “Ha, I made you say underwear”
You’ll need the Salvation Army when i’m finished with you!
Pete and Repete were in a boat . . .
What were you eating under there?
The classic juvenile response when someone sticks out 
their tongue at you:
“No thanks, I use toilet paper.”
Great responses! Hoo boy, I’ll get her good now.