Justin and Hailey Bieber's 6-month-old son, Jack, got in on his dad's birthday festivities! Two days after the signer turned 31, he posted more photos from his celebration, with one of them featuring the new father holding his adorable tot.

Justin Bieber turned 31 on Saturday and shared some photos of himself celebrating his birthday with family and friends, including a sweet family snap of him, Hailey and Jack Blues