Baby Duke is growing up so fast!
PHOTO: See how Giuliana Rancic and Bill Rancic's baby Duke celebrate St. Patrick's Day
“Good luck on @HSN today mommy!!! I will be watching from our crib with this smile on my face. Love Duke,” Bill wrote along with a photo [see above].
In the snapshot, the brown-eyed sweetie pairs his ear-to-ear grin with a furry animal hat – and shows off his first baby tooth.
PHOTO: Bill and Giuliana Rancic's Duke has a sweet snack
After a fan tweeted the proud parents saying, “OMG he's getting a tooth! what a cutie,” the E! News host responded, “Yes! His bottom tooth!”
This latest milestone comes just weeks after Giuliana shared another exciting event in little Duke’s life.
During their recent vacation in Hawaii, “[Duke] had his first swim lesson!” the 37-year-old told Life & Style. “He loved it! He’s a little fish!”
EXCLUSIVE: Inside Bill and Giuliana Rancic's Hawaiian Vacation
Hopefully the adorable 7-month-old will make a guest appearance on his parent's new NBC dating series Ready for Love, which premieres March 26.