Hollywood remakes of foreign-language films are usually safe targets for criticism, but in this case screenwriter Paul Haggis (Crash, Million Dollar Baby) has turned the Italian romantic comedy L’Ultimo Bacio (2001) into something smarter, funnier, and more penetrating. The plot hasn’t changed much: four pals in their late 20s fight a losing battle with adulthood, and one of them (Zach Braff), unnerved by the pregnancy of his longtime girlfriend (Jacinda Barrett), strays into an affair with a seductive teenager (Rachel Bilson). But Haggis, who’s in his early 50s, has carved a jagged edge into the subplot involving the girlfriend’s embittered parents (Blythe Danner and Tom Wilkinson, both superb), whose long and painful marriage is finally coming apart at the seams. The counterpoint between the two couples and their ongoing dialogue on the price of fidelity unexpectedly turn this youth comedy into a movie for grown-ups. Tony Goldwyn directed; with Casey Affleck, Cindy Sampson, and Harold Ramis. R, 115 min. Century 12 and CineArts 6, Crown Village 18, Gardens 7-13, Lake, Norridge, River East 21, Webster Place.