Is Gwen Stefani throwing a big, birthday celebration for her man Blake Shelton this weekend? It’s very possible because she was spotted last week at a novelty shop in Hollywood stocking up on lots of fun party supplies. It’s been about three weeks since Blake helped Gwen’s oldest son celebrate his 10th birthday by letting him drive a buggy on his Oklahoma property and taking him on a helicopter ride to his performance before the Indianapolis 500. Blake and Gwen have become quite the party planners. We can’t wait to hear what kind of 40th birthday bash takes place this weekend!