Oh my gosh, this is so cute ... our insides are exploding!

Josh Duhamel wins the award for best husband and most adorable father today! The hunky actor posted a pic on his Instagram of their adorable son Axl wishing mama Fergie a happy 39th birthday with an oh-so-heartwarming sign.

Along with the pic of his baby boy, who will be seven months on March 29, the Safe Haven star wrote, "#happybirthdaymommy."

Our hearts are melting!