In case you didn't know, Zac Efron has a 23-year-old brother named Dylan. Although Zac has been in the limelight since his childhood years, Dylan has remained pretty much unknown… but if this latest update is anything to go by, he could have a pretty solid future as a Calvin Klein model.

The brothers have been pictured before at basketball games in Los Angeles, and although Dylan keeps private on social media, sibling photos do pop up from time to time on Zac's Instagram and Twitter pages.

The 17 Again star is currently enjoying a break from filming in Hawaii, and has been fitting in some family time while he's there. The buff actor posted a photo earlier this morning of himself and Dylan enjoying their night on the beach… while topless of course. And we have to say, it looks like Zac has some serious competition in the six pack department.

The swoon-worthy photo was captioned "#brothers" and in just five hours already has 330,000 likes. Not bad for a night's work.

Zac is currently living on Oahu in Hawaii, close to the set of his latest film, Mike and Dave Need Wedding Dates, also starring Adam DeVine, Anna Kendrick and Aubrey Plaza. As well as a visit from his little brother, the actor was also recently joined by his girlfriend, model Sami Miro for some quality couple time.

 

A photo posted by Zac Efron (@zacefron) on

We bet he'll be gutted when filming finally finishes!