The Black Eyed Peas singer turned 39 on Thursday (27Mar14), and her husband of five years declared his love for her by showing off their seven-month-old son.
Duhamel took to Instagram.com to post a photo of the tot sitting in his dad's lap looking straight into the camera, while the actor held up a sign reading "Happy Birthday Mommy!!!"
Fergie later took to the photo sharing website to post a picture of her one-of-a-kind birthday cake, complete with red frosting, rose decorations and a shirtless photo of her hunky husband from his film, Win a Date With Tad Hamilton.
She wrote the caption, "Thank u (sic)... for my dope bday (birthday) cake!!!!! Lol (laugh out loud). Tad Hamilton."