The hotties were spotted hanging out together Tuesday night at Bootsy Bellows in West Hollywood, along with The Lying Game actor Ryan Rottman and Joe Jonas, laughing and chatting with each other.
According to People, the Neighbors star kept a low profile in the hot spot, sticking to his sobriety, sipping Fiji water in the club's back VIP room with his pals. A source told the mag Zac looked "happy and relaxed" while he was there, and didn't care about who else was at the club or what was going on. Rob, meanwhile, sipped cocktails and chatted with the rest of the group.
Earlier in the night, they kicked off their guys' night out at Pinz Bowling Alley in Studio City, Calif., according to E! Online, where they played several games until midnight. After that, they left the bowling alley with three girls and went to a house.
Speaking of hanging out, Zac was spotted leaving his rumored ladylove Michelle Rodriguez's Los Angeles home Sunday after enjoying a night out with friends at Chateau Marmont Saturday. Rob was also there, a source told the site, chatting it up in the back garden of the hotel.