Netflix thought I would like this slightly better than I actually did. But overall, not a bad way to waste an evening.
A twenty-year high school flashback sets things up: student Bob Weirdicht (Dwayne Johnson) is a fat, friendless loser; Calvin Joyner is the generally acknowledged star of the senior class. A cruel prank (near Carrie level) is played on Bob; alone among his classmates, Calvin shows him a random act of kindness.
In the current day, Calvin's life trajectory has not turned out the way anyone expected: he's a midlevel accountant. Although he does have a hot wife, his high-school sweetheart. Out of nowhere, Bob, now calling himself "Bob Stone", shows up, looking like… well, Dwayne Johnson. He is ebullient, ingratiating, pushy, hilarious; Calvin has little choice but to go along on the ride. But it soon develops that Bob's on the run from his employer, the CIA, and needs to go rogue, because he's been set up to take the fall over the theft of critical US secrets.
That's his story anyhow.
Hey, does anyone remember The In-Laws, a 1979 movie with Alan Arkin and Peter Falk? It's a lot like that. Uncredited, as far as I can see.
Anyway, it's rated PG-13 for (I assume up to the PG-13 limit) "crude and suggestive humor, some nudity, action violence and brief strong language." The Johnson/Hart chemistry works OK, Johnson has some strong comic chops, but not enough to support a whole darn movie.