Forget “The Rules.” Skip “The 5 Love Languages.”

The wittiest, most instructive, most sobering new book about romance is Adelle Waldman’s novel, “The Love Affairs of Nathaniel P.”

This darkly comic story is about an ambitious young New Yorker who’s just signed his first book deal. Attractive, smart, sensitive and liberal, he’s every woman’s dream. Except that he’s also maddeningly self-absorbed and subtly manipulative in ways that will drive a series of girlfriends insane.

In honor of Valentine’s Day, I asked Waldman to write one more scene: Nate picking out a romantic gift for a certain someone special. So here it is — a Washington Post exclusive for Feb. 14:

Because Greer had often said Valentine’s Day was a stupid holiday made up by greeting card companies, Nate wasn’t planning on getting her anything. But the day of, he wondered if that was a mistake. Perhaps she’d be mad if he showed up empty-handed?

He decided it would be best to hedge his bets by getting her something “ironic,” such as, a box of chocolates in a package so corny it could only be meant with a wink. On his way home to the apartment he and Greer recently moved into, he stopped at a drugstore. But when he saw the selection, he began to worry. The heart-shaped boxes of chocolates were corny — but maybe not so very corny. What if she didn’t realize he meant this ironically? She would think he put no thought into it and simply got her a slightly tacky box of drugstore chocolates in total earnestness. But Nate didn’t know what else to do. The only florist’s shop he could think was a subway stop away, and it was cold and rainy, and he’d be very late to dinner if he went there and back.

He began pacing the Valentine’s Day aisle. Finally, he happened to see, tucked away near the end of the aisle, a pink box — called “The Box of Love.” Through a plastic window, Nate could see that the Box of Love contained two champagne flutes with hearts on them and a small, malevolent-eyed teddy bear wearing a bib with the words, “I love you” printed on it. It was so hideous it could only be meant ironically.

He had found Greer’s gift.