• Share
  • Tweet
  • Share
Jessica Simpson, Eric Johnson

Juan Sharma/Bruja/PacificCoastNews.com

Jessica Simpson is one hot mama.

Just two months after giving birth to son Ace, the fashion mogul stepped out to celebrate fiancé Eric Johnson's birthday looking svelte in a cleavage-baring black mini dress, paired with a black-and-white printed blazer.

"Birthday weekend!!! I love you with everything and more and more and more…," Simpson tweeted Saturday, along with a photo of her and her hubby-to-be.

The couple reportedly headed to a Teppanyaki restaurant in Santa Monica, Calif., to kick off the celebration, where they feasted on Japanese food, according to the Daily Mail, and capped off the night with a trip to a nearby bowling alley.

The former NFL footballer will ring in his 34th birthday Sept. 18.

The mother of two, who welcomed the couple's second child together June 30, told Us Weekly she's been "focused on feeling good and making healthy choices," following the baby's birth.

And it's certainly paying off.