HARLEZ-VOUS FRANCAIS?
Can you drive a French motorcycle?

EX POST FUCTO
Lost in the mail.

IDIOS AMIGOS
We're wild and crazy guys!

VENI, VIPI, VICI
I came, I'm a very important person, I conquered.

COGITO EGGO SUM
I think; therefore I am a waffle.

RIGOR MORRIS
The cat is dead.

RESPONDEZ S'IL VOUS PLAID
Honk if you're Scottish.

QUE SERA SERF
Life is feudal.

LE ROI EST MORT.  JIVE LE ROI
The king is dead.  No kidding.

POSH MORTEM
Death styles of the rich and famous.

PRO BOZO PUBLICO
Support your local clown. (or politician, your call)

MONAGE A TROIS
I am three years old.

FELIX NAVIDAD
Our cat has a boat.

HASTE CUISINE
Fast French food.

VENI, VIDI, VICE
I came, I saw, I partied.

QUIP PRO QUO
A fast retort.

ALOHA OY
Love; greetings; farewell; from such a pain you should never
know.

MAZEL TON
Tons of luck.

VISA LA FRANCE
Don't leave your chateau without it.

AMICUS PURIAE
Platonic friend.

L'ETAT, C'EST MOO
I'm bossy around here.

COGITO, ERGO SPUD
I think, therefore I Yam. (OK, more than one letter.)

VENI, VIDI, VELCRO
I came, I saw, I stuck around. (OK, another exception.)

My personal favorite:

VENI, VINI, VISA
I came, I saw, I charged.