Kids, even the wimpy ones, grow up so fast. It’s hard to finish a film franchise with them before they’re shaving, dating and turning up in the tabloids.

Zachary Gordon, the fresh-faced lad who landed the coveted “Wimpy Kid” role in the adaptations of Jeff Kinney’s “Diary of a Wimpy Kid” movies, has had a growth spurt. His Greg Heffley is taller than his portly pal, Rowley (Robert Capron), almost tall enough not to have to take any more guff from his bullying older brother, Rodrick (Devon Bostick).

Greg’s voice has changed. But in the summer before he goes into 8th grade, he’s still inept around girls, still lying to his parents, still self-absorbed and rude to others.

The lying is what he does to “make a connection” to the pretty blond Holly Hills (Peyton List). And to get to her, he takes advantage of Rowley and Rowley’s parents — members of the country club where Holly plays tennis. Greg crashes the 1 percent enclave.

What’s new here is Greg’s disconnect from his long-suffering dad, played with commitment and comic skill by Steve Zahn. Dad’s the one who can’t quite figure out how to disconnect the video game so that Greg is forced to play outdoors — so he unplugs the whole TV.

Dad enlists Greg in his Civil War re-enactment company — and the South rises again. He takes the boy fishing, only to find he’s squeamish at the sight of worms. He gets a dog, hoping the kid will learn responsibility. The dog takes over the house. And Dad re-joins his old Wilderness Explorer troop so that Greg will learn to camp.

None of it works. “We have nothing in common,” father and son admit.

Dad wants his boys to be on a par with a jerk-jock neighbor’s kids. Good luck with that.

Greg only wants to play video games and impress Holly, and the lengths he goes to lead to his biggest mistakes.

“Dog Days” is not the best of the “Wimpys,” but Bostick is still a laugh a minute as Rodrick, and for an hour the laughs come quick and sure — slapstick stuff, mostly.

And for parents and their tweens, that’s enough to keep this, the kid-friendliest film franchise of them all, from being a disappointment.