Jessica Simpson walked down the aisle again ... but she wasn't the bride.

The singer -- who has been in the wedding party for at least two other friends in the past -- played bridesmaid this weekend and put her growing baby bump on display doing it.

Sporting a tight black dress and turquoise jewelry, Jess looked ready to pop on Saturday. The San Diego ceremony was for her friend Kathryn Sykora and one of Eric Johnson's buddies.

Jessica and Eric are due for a wedding of their own soon, but probably not until after the 32-year-old gives birth to the couple's second child.

Shouldn't be long until Simpson gives birth ... see how her stomach has grown throughout her second pregnancy in the gallery above!

Hot Videos