Chris Pratt celebrated a milestone birthday with his oldest child.Pratt, 46, reveled in the fact that he now has a teenager at home as he honored his son Jack on his 13th birthday.The "Guardians of the Galaxy" star shared a rare gallery of fun times on social media Sunday to mark Jack's big day. Pratt and his ex-wife, Anna Faris, welcomed Jack in 2012 and have co-parented since their split in 2017.CHRIS PRATT DEBUTS DRAMATIC NEW LOOK WITH FAKE BLOOD AND BEARD"I have a teenager???" Pratt wrote over a collection of images shared to his Instagram stories. "Jack, I can't believe