Gwen Stefani paid tribute to her eldest son,Kingston, Tuesday on his 14th birthday. She shared a photo of Kingston at the beach, captioning it, “happy 14th bday to my first born son -thank u God for marking me HIS MAMMA GX #loveukingstonjames” In another post, she shared a video of her boyfriend Blake Shelton smothering Kingston with birthday kisses on his cheek (so cute!). Gwen is mom to three boys with ex-husband Gavin Rossdale: Kingston, 11-and-a-half-year-old Zuma and six-year-old Apollo.