Masticating a choice piece of tenderloin.
Visiting the rectory.
“Are you sure you were talking about waterskiing? From where I sat it looked like you were conjugating some irregular verbs.” --Grace Kelly, in To Catch A Thief
Yes! Right before she and the French girl have a cat fight! “How about if we stand in shallower water and continue this discussion about whether I’m a little girl” (or something like that).
Well done - thanks!
How about a single word?
Niggardly.
Perfectly good word, forever tainted due to ignorance.
sigh
Not quite a “dirty” connotation - but a phrase uttered by a hapless nitwit who was convicted of being an accomplice in the Monster of Florence serial murder case, attained lasting notoriety in Italy.
Mario Vanni (a.k.a. il Torsolo (Apple Core), while on trial repeatedly referred to his associates as “picnicking friends”. Soon this became a popular slang term referring to hanging out with sleazy types and being up to no good. “Did you have fun with your ‘picnicking friends’?” 
What’s unfair is the planet with the most beautiful name is the one that gets made fun of the most.
By the way, I have pictures of an eruption from Uranus if anyone wants to see.
Not a phrase, so much as a name:
Dick Trickle
I wish I could recall the exact quote and circumstances, but one time at dinner I was discussing something with my Mother-in law (probably the food) and in reference to Her Majesty The Queen, I finished a sentence with the phrase “pluck her partridge”. She gave me a funny look as though I had just said something ribald, and I realized it might be thought of in that way soon after I said it, but was entirely unintentional and off-the-cuff.
Happened just tonight, when I asked my wife: “Do you want me to warm up your buns before I stick the weiners in?”
Lickedy split. Filthy!!
Leaky burrito.
LOL at these!!
I’m going to defenestrate her tonight.
Where’s her “tonight”?
“You always were a cunning linguist, James” (Bond), by Miss Moneypenny in a Bond flick when he said he “was brushing up on his French” while in bed with a gal.
From a former cow-orker looking at an antique wall map:
What’s with the “cum” in
*Mare
Pacifi-
cum*
Polling the electorate.
That actually means shut the f*** up.
Big Beaver? You gotta keep going until you’ve got Quarton.