Blackout victim: It was so dark that night I couldn’t even see the arm up my ass.
Word of advice: Keep your friends’ arms close, and your enemies’ arms up your ass.
Now that’s the spirit, BrightNShiny!
Episcopalians: While we don’t actually condone you having an arm up your ass, we still minister to those who do.
Dom/me: You will have my arm up your ass and LIKE it!!
Pain Slut: Is that all the arms you have?
Submissive: May I PLEEEEEASE have your arm up my ass?
H.P. Lovecraft: And in the moment before I mercifully lost consciousness in the depths of stygian forgetfulness, I realized that the hand was coming from an arm up my ass.
The Rock: It DOESN’T MATTER whose arm is up your ass!
Hulk Hogan: Whatcha going to do, brother, when Hulkmania’s arm is up your ass?
Freud: Your fears stem from an arm-up-the-ass envy of your father.
Jung: The arm up your ass symbolizes your feelings of being dominated and the need to be fulfilled.
pitchforkmedia.com: The media sticks their arms up the asses of these so-called “garage revival” bands claiming to save rock and roll, which apparently means shitting all over it, putting it in a bag, and setting it aflame on Keith Moon’s grave.
JANEWAY!
really raising the tone of the SDMB here, aren’t we? 
POTC fan: YARR!! There be an ARRmm up me ARRse!
St. Thomas Aquinas: how many arms can fit up the ass of a dancing angel?
American Pie: “So, how does it feel?” “Like…an arm up your ass.” “Really?” “Oh, yeaaaaah.”
St. Nicholas of Myra: Who stole the arm up my ass? In any case, I guess I deserved it.
The Polyphonic Spree: No, our robes don’t just hide the arms up our asses!
Marx: The arm is the opiate of the asses.
Saddam Hussein: There are no arms up my ass…really…you can look if you want to!
(frantically trying to formulate a joke about a large animal veterinarian giving a proctological exam to a 4 legged beast of burden. Ah…having his arm up an ass’s ass)
Monarchy: Only a few select individuals enjoy the privelage of sticking their arms up the asses of the masses.
Alternately, “Batman vs. the Arm up his Ass?”
Mythos: The eldritch tendrils of the Great Old Ones are up your ass, languorously consuming you from within.
You have these the wrong way round 
BASIC: You shove your arm up your ass slowly and bloatedly.
Assembler: You shove your arm up your ass quickly but painfully.
C: You shove your arm up your ass as quickly, but as painfully as with assembler.
COBOL: You get mediavel on your ass.
LISP: I’ve got an arm up my ath, thomeone, help!
C++: The object up your ass has been instantiated as an arm.
I so want this for my sig.
LISP: (I’ve got (an arm (up my ath)), thomeone, help (it (is uncomfortable)))!
Rube:
[sub]([/sub]
\----@
[sup]([/sup]
("@" is the closest symbol to a fist that I could think of.)
Star Trek: The Next Generation - Can Wesley save the ship again with an arm up his ass?
Orthodox Jewish: Unfortunately, removing your arm from my ass would be work on the Sabbath, so it must remain there until sundown.
Ava