John Stamos’ 4-Year-Old Son Billy Looks So Grown Up Joining Dad For NYC Trip

Have mercy, John Stamos’ baby boy looks all grown up! The “Full House” alum shared a carousel of pics to his Instagram on Tuesday showing off his recent trip to New York City with his 4-year-old son, Billy. The little heartthrob posed alongside his dad in a plaid puffer coat and a green knit beanie. The father-son duo also saw the Broadway musical “Beetlejuice.” Plus, Billy sported a red velvet suit while on stage with his dad at Carnegie Hall, where the 59-year-old musician performed on Dec. 5.