Of American-English origin, the phrase to be caught with one’s pants (or with one’s trousers) down means: to be caught off-guard; to be surprised in an embarrassing or compromising situation.

This phrase occurs, for example, in Seven apologies for an apology, by the British journalist and author Max Davidson, published in The Daily Telegraph (London, England) of Saturday 20^th November 2010:

Deflecting the blame

Ever since Adam grassed Eve up in the Garden of Eden (“The woman gave to me and I did eat”), people caught with their trousers down, their foot in their mouth or their hand in the till have sought scapegoats. But it is not gallant to blame other people for your own shortcomings. Remember all those MPs who tried to foist the blame onto the House of Commons Fees Office? Don’t fall into the same trap.

The earliest occurrences of the phrase to be caught with one’s pants (or with one’s trousers) down that I have found are as follows, in chronological order—perhaps significantly, many of these early occurrences are from newspapers published in Kansas:

1-: From one of the unconnected paragraphs making up the column Local Items, published in the Washington Post (Washington, Kansas, USA) of Friday 2^nd April 1886:

—What is this world coming to anyway? And why are my friends so unfortunate? Sister Molloy is in the toils for murder and now Doc. Krohn has been caught with his pants down. I am almost afraid to move for fear they will catch me at some thing wrong.
—Wm. Allen.

2-: From the following advertisement, published in The Torch of Liberty (Mound City, Kansas, USA) of Thursday 10^th May 1894:

SHOES MAY COME FROM “SHOERUSALEM,”
AND PANTS FROM “PANTSYLVANIA.”

But ours did not.—They came from the Eastern factories that were hard up, and we caught them

WITH THEIR PANTS DOWN!!

Hence we got some wonderful bargains. And now, dear friends, you have caught us in the same predicament that we caught the other fellows in, i.e. we have 100 Pairs of Pants that are “way up stuff” and yet they are way down. As is our new line of dress goods, Shoes, Hats of all kinds, and a large assortment of miscellaneous goods. We sell all these goods at about

ONE-HALF OF FORMER PRICES.

Remember, these are facts in cold, logical English, and we will back what we say with goods and prices. Our goods are not all in but will soon be here. Come and examine our stock. Respectfully Yours,

THE H. A. STRONG MERCANTILE COMPANY.

3-: From one of the unconnected paragraphs making up the column City in Brief, published in The Mattoon Gazette (Mattoon, Illinois, USA) of Friday 3^rd August 1894:

—Considerable quantities of oats and wheat were caught with their pants down by the heavy rains of Saturday and Sunday, but little damage is reported.

4-: From the following advertisement, published in The Belle Plaine News (Belle Plaine, Kansas, USA) of Thursday 4^th October 1894:

Gentlemen.

Don’t be caught with your pants down anymore when you can buy suspenders at the Racket at cost.

5-: From the Western Spirit (Paola, Kansas, USA) of Friday 15^th May 1896:

IN speaking of his candidacy for State Treasurer, King David swore against Lewelling the other day saying: “I’m not going to be caught again with my pants down!” As we understand the story, it wasn’t Lewelling who did it.

6-: From Editorial Comment, published in The St. John Weekly News (St. John, Kansas, USA) of Friday 24^th December 1897:

Instead of being in Washington at the opening of congress, Jerry Simpson stayed in the district fixing up his political fences where McKay, Titus and Brown of Pratt, have stampeded the populist herd through. At first in is said Jerry treated the opposition to him as a huge joke, but of late he came to look upon it as rather serious. It is reported that Jerry recently said that a man’s day in public life comes sooner or later and that he has been preparing for it by laying up something for a cold day; that he is too old a fox to be “caught with his pants down”.

7-: From the Blue Valley Blade (Seward, Nebraska, USA) of Wednesday 2^nd March 1898:

—Uncle Sam evidently does not intend to be caught with his pants down in the event of a scrap with Spain, judging from the activity displayed in all branches of the army and navy departments. If war must come Spain will find this country ready.

8-: From an article about corruption in the Republican local administration, published in The Minneapolis Times (Minneapolis, Minnesota, USA) of Saturday 1^st October 1898—the following is from the testimony given by a detective, B. F. Dodson, during the trial of Alderman Drew, who had been indicted for soliciting a bribe:

I asked how this money was to be paid—in checks, drafts or currency, and Mr. Drew remarked that checks and drafts could be very easily traced, and if it ever come to a show-down he didn’t want to be caught with his pants down and he preferred currency, as currency couldn’t be so easily traced.

9-: From the following advertisement, published in the Fall River Daily Herald (Fall River, Massachusetts, USA) of Friday 16^th June 1899:

DON’T DO IT

IN the Franco-German war a small detachment of German troops were guarding a large number of French prisoners. As the Germans were in the enemy’s country, extreme watchfulness was necessary, as the prisoners were ready to run at any moment. Finally a young officer made a brilliant suggestion, and it was promptly carried out. He ripped the suspender buttons from the prisoners’ trousers, and took away their belts and suspenders. After that their hands were so busy holding up their trousers that fast running was out of the question.

THAT’S THE WAY

The Bulls (on wheat) have got the Bears fixed, the Bears are so busy holding up their trousers (putting up margins) that they are too busy to sell any more wheat “short,” otherwise they might find themselves in the predicament of the boy whose father found him going in swimming against his orders, and coming up to him unexpectedly, caught him with his trousers down. If you do not want to be caught that way—Buy Wheat! Buy It on every recession, $25 will margin 1004 [?] bushels. Our free book explains it. Send for it.
Howard, Crosby & Co., 24 Congress St., Boston, Mass.