The daughter of musician Quincy Jones and actress Peggy Lipton has proven herself a fine comic actress in film (I Love You, Man) and television (Parks and Recreation), and now a surprisingly sharp screenwriter in Celeste & Jesse Forever — not only the smartest and funniest romantic comedy you’re likely to see between now and New Year’s, but the smartest and funniest anti-romantic comedy, too.

She and Saturday Night Alive alum Andy Samberg warmly portray the title twosome, seemingly struck from the same demented mold with their odd humor and little reindeer games. She’s a trend forecaster; he’s an artist; and they really are best friends.

It’s just too bad they’re getting divorced.

Yet they continue to go about life as if things aren’t any different. This alarms their friends, who think Celeste and Jesse are as made for each other as humanly possible.

Wrong, says Celeste: “I love Jesse dearly, but he doesn’t have a checking account. Or dress shoes. The father of my children will have a car.”

Co-written with fellow actor Will McCormack (TV’s In Plain Sight), the thoroughly winning film, opening Friday, flies high on dialogue like that, but delivered so deftly by all that the situation at heart maintains realism — a much-welcome respite from the madcap, overblown buffoonery Katherine Heigl, Jennifer Aniston and Cameron Diaz insist on fronting ad nauseum.

And like real life, its third act doesn’t play out as expected.