SON, MAYBE IT’S TIME WE TALKED ABOUT THE BIRDS AND THE BEES: Father and son Noah Levenstein (Eugene Levy, left) and Jim Levenstein (Jason Biggs) sit down for a heart to heart talk when Jim comes home to East Great Falls, Michigan, with his wife and child (not shown) for his and his wife’s high school class’s thirteenth reunion.

To some, it probably seems like only yesterday that the high school seniors in American Pie were on a mission to lose their virginity before their graduation. But that was actually two sequels (American Pie 2 and American Wedding) and four spinoffs ago, and the high school friends have long since graduated and gone their separate ways.

Thus, at the point of departure we find that Jim (Jason Biggs) has married former band geek Michelle (Alyson Hannigan) and the couple are raising a toddler (George Christopher Bianchi) who gets into everything. Meanwhile, Oz, the jock (Chris Klein), is now a high-profile TV sportscaster in Los Angeles; Kevin (Thomas Ian Nicholas) is married and working as an architect; and Finch (Eddie Kaye Thomas) is a bohemian fantasizing about doing something more daring than managing a Staples store in New Jersey.

As middle-age approaches, the buddies decide to put their lives on hold and return to East Great Falls to attend their 13th high school reunion. There, they encounter former classmates Stifler (Seann William Scott) and The Shermanator (Chris Owen); Kevin’s ex-girlfriend, Vicky (Tara Reid); Oz’s ex-wife Heather (Mena Suvari); as well as Stifler’s mother (Jennifer Coolidge); and Jim’s father (Eugene Levy).

In the ensuing weekend, the band of friends reminisce and become embroiled in sordid affairs and sophomoric hijinks. For example, Kevin gets so drunk that when he wakes up in bed with Vicky, he can’t remember whether he’s cheated on his wife (Charlene Amoia). Jim is pursued by his 18-year-old next door neighbor (Ali Kobrin) whom he used to babysit.

Frankly, the group is a little long-in-the-tooth to over-imbibing in alcohol, ecstasy, and sex. A telltale sign that the cast members might have run its course is the lack of enthusiasm (other than Eugene Levy and Seann William Scott) with which they deliver their lines.

Good (**). Rated R for nudity, profanity, drug use, teen drinking, crude humor, and graphic sexuality. Running time: 113 minutes. Distributor: Universal Pictures.