Vacation Vacation

Apparently cluelessness is hereditary.

In the first trailer for the reboot of National Lampoon's Vacation, it's clear that Rusty Griswold (Ed Helms) approaches family road trips with the same blind optimism as his father Clark (Chevy Chase) did in the original movie.

See the first photo from the National Lampoon's Vacation reboot

In the new Vacation, which comes out this summer, Russ decides to re-create his own childhood trip to Walley World with his wife Debbie (Christina Applegate) and their two sons. Along the way, they stop at a "hot spring" that turns out to be a sewage repository, and Russ gives his son a misinformed explanation of rim jobs. There's also a winking reference to the fact that "the new vacation will stand on its own." (Get it?)

But the most eye-popping part of the trailer comes during an overnight stop at Russ' sister Audrey's (Leslie Mann) house, where Russ and Debbie learn that Audrey's husband, played by Chris Hemsworth, is quite well-endowed, to say the least. (Also, his name is Stone Crandall.) We don't blame you if you pause the trailer at this point - it's a real marvel.

Check out the trailer below (Warning: NSFW). Vacation hits theaters July 31. Will you see it?