Zac Efron Shares Shirtless Thirst Traps From Idaho Vacation With Brother Dylan

Zac Efron's got one of the best bods in all of Hollywood ... though he's got some serious competition within his own family.

The actor just shared a series of shirtless thirst traps from a recent getaway to Idaho with his brother Dylan, who is giving his more famous sibling a run for his money when it comes to hotness.

Zac and Dylan both ditched their shirts during a boat day out on Lake Coeur d’Alene, where they showed off their abs and chiseled bodies as they did some wakeboarding.

The Efrons also hit the links for a round of golf ... and Dylan says Zac came out on top ... though Dylan says he got revenge by pushing Zac into the lake.

There are a lot of thirst traps, but also some wholesome family content ... and even some snaps of Zac falling off his wakeboard.

Zac's always been known as a super hottie but his Hollywood producer brother is coming in hot here soo ... so we gotta ask.