This is a column about sex.

Do I have your attention? Yes? Right. Good.

Greta Scacchi, who, if I were in the business of ranking my favorite actresses, would land in the top five, caused a minor stir on the set of her latest Merchant-Ivory art flick, "Cotton Mary."

For those unfamiliar with the British (by way of Milan, Italy) actress, Ms. Scacchi's most famous Hollywood film role is as the doomed Caroline Polhemus in 1990's "Presumed Innocent." Before that, her résumé included "White Mischief" (1987) and "The Coca-Cola Kid" (1985).

She turned down the career-making role in "Basic Instinct" that eventually went to Sharon Stone and instead accepted a near career-killing role in 1991's absurd thriller "Shattered." Luckily, Greta was able to rebound with a starring role in the TV miniseries "The Odyssey" (1997) and her Emmy-winning performance as the Russian Empress Alexandra in the 1996 HBO film "Rasputin."

The controversy came when her young son, born in October of last year, visited the set.

Ms. Scacchi's second child -- she also has a daughter from her former marriage to actor Vincent D'Onofrio ("Full Metal Jacket," "The Thirteenth Floor") -- is the product of her present relationship, which just so happens to be with her cousin, Carlo Mantegazza.

Romantic relationships between cousins, especially between first cousins, are usually the stuff of jokes, as I'm sure most Southerners can wearily attest. If you admit to having fallen for a cousin, you're likely to end up on "The Jerry Springer Show" or, worse still, on "Sally Jesse Raphael."

We all know that rap. Most people view "kissing cousins" as illiterate rednecks, the spawn of already-shallow gene pools, poor souls destined only to add more stagnant water to the mix.

The facts, of course, beg to differ.

For instance, I looked up the various state laws regarding marriage between first cousins and found some interesting details. Alabama, bowing to stereotype, does allow first cousins to marry. But Mississippi and Arkansas, two states Alabamians are permitted to look down upon, do not.

On the other hand, the supposedly enlightened states of New York and California both allow first cousins to marry. (How come there are no jokes about inbred city dwellers?)

Still other states, such as Arizona, adopt a more scientific approach. First cousins there may marry, but only if there is no chance of their having children.

As it turns out, Southern states are no more likely to allow cousins to marry than are Northern states, and mostly rural states are no more likely than are their largely urban counterparts.

Still, the idea of romantic involvement between cousins is, well, icky, at least under most circumstances.

But when someone such as a moderately famous, award-winning and decidedly upper class actress has a sexual relationship with her cousin, it seems strangely romantic. It's somehow different from all those fabled redneck couplings because it harkens back to the days of aristocracy, when marriages between cousins were common. After all, such marriages kept the nobility's hard-earned money (or hard-stolen, depending upon your ideology) in the family.

You almost can't read a Victorian novel without coming across at least one pair of lovesick cousins, as in Thomas Hardy's "Jude the Obscure," which recently found its way to the screen as a film starring Kate Winslet.

It all comes down to class. That is why Ms. Scacchi's latest romantic dalliance is only worth minor note and not tabloid headlines. And it's why when poor, white Southerners do the same thing, they find they're the talk of the trailer park.