Gavin Rossdale treated Kingston to a smoothie from Starbucks out and about looking badass in his backwards hat yesterday. It was a big weekend of celebrity kid birthday parties for Kingston and a wedding anniversary for Gavin and Gwen, but Monday was all about the hot dad spending time with his oldest son. While we've yet to see baby Zuma, Kingston remains one of our favorites with his style and attitude. Speaking of adorable kids, don't forget to check it out — lilsugar is teaming up with GAP for their third annual casting call so your little one could be their next star!