Arnold Schwarzenegger, 73, proved he’s a proud dad when he gave a shout-out to his lookalike son Joseph Baena on his 23rd birthday on Oct. 2. The actor shared a cute photo of the hunk standing in what looks like a filtered and/or photo-shopped photo of a club while wearing headphones and lifting his arms up with a big smile. “Happy Birthday! love Dad,” was written over it in red ink.