Moral Turpitude

So to MJ's relief we survived the 10 hour flight with relatively little turbulence, no engine failure
and no terrorists on board. We also survived US immigration having assured officials that amongst many possible misdemeanours we were neither guilty of importing snails nor of "moral turpitude". Does anyone actually know what moral turpitude means we found ourselves asking a random selection of locals congregated around the Boudin Bakery bar at Fisherman's Wharf.
"Are you able to tell us Al?" we asked of a guy who was the image of Al Pacino. After he had
adjusted his baseball cap so that the peak faced backwards, donned a pair of very dark sunglasses just as the lights of the bar dimmed, and drawing on a dead cigar butt that he'd fished out of his bag "I have no idea" he muttered. "But d'ya know what? I get that all the time -
Al Pacino - Yeah all the time."
Maybe the very gay bartender could enlighten us then? "I think it's to do with good behaviour" he answered cagily. "Immigration gave me a tough time getting back in when I returned from
New Zealand to San Francisco." "So could it be something to do with "men behaving badly"
As we ordered our third large glass of Californian Chardonnay we found ourselves caring less and less about moral turpitude and became more interested in devouring the delicious deep-fried calamari with french fries that he served us. Soon it was way past 4 in the morning to us so we finally gave in to our jet lag. On the cable car back to the hotel we passed a theatre advertising "nude male review". We thought that sounded interesting but decided to give it a miss as we didn't want to be found guilty of moral turpitude on our first night!