New York ? Oh, behave!

It turns out British guys don’t have as stiff an upper lip as we thought – at least not in bed.

In fact, Americans can learn a lot from them when it comes to having fun in the sack. Or so says Men’s Health magazine.

Guys in the U.S. rank an embarrassing 10th on a list of 20 countries surveyed on sexual satisfaction by the magazine for its September issue, on sale Tuesday. British men rank first in the survey.

Even more shocking was the dead-last placement of Italy, long revered for its romance.

“My guess is that in Britain, where chivalry was invented, the women are actually getting more gentlemanly attention and conversational interplay with their guys,” reasoned Men’s Health Editor-in-Chief David Zinczenko, “while the Italian men think they don’t have to bother, because they are by definition great lovers.

“Who would have a greater incentive to please his woman?” he asks. “A guy whose skills are suspect, or a guy who already thinks he’s the hottest thing since Marcello Mastroianni?”

Men’s Health rated sex lives based on marriage and divorce rates, number of partners and frequency, sexual satisfaction and affairs.

What brought American men down is that they’re having sex less than twice a week on average. The only two countries where guys get it on less are Germany and Malaysia.

More than half of British men say they’re happy with their sex lives, and only one in seven has had an affair, compared with more than a quarter of Italians who claim to have cheated on their wives.

That held Italy back, along with its increasing divorce rate and the fact that only 36 percent of guys say they’re happy in bed.