Article continues below advertisementArnold Schwarzenegger is one proud dad - and he's definitely not hiding it.The Hollywood icon recently lit up social media after sharing a behind-the-scenes moment from the Arnold Classic, where his son Joseph Baena hit the stage.Article continues below advertisementIn a clip that quickly made the rounds online, Schwarzenegger couldn't stop smiling as he filmed Baena confidently posing under the bright stage lights. He stayed close to the action, clearly soaking in every second as his son flexed and showed off his physique.