Pop star Jessica Simpson and former House actress Odette Annable turned bridesmaids on Saturday (15Jun13) as they attended a pal's wedding in California.

Heavily-pregnant Simpson braved the heat and donned a fitted black gown for interior decorator Kathryn Sykora's nuptials to former American football star Chris Hetherington, who is friends with her retired athlete fiance Eric Johnson.

The couple exchanged vows at the Rancho Bernardo Inn in San Diego, where Jessica's singer sister Ashlee Simpson and newly-married former personal assistant CaCee Cobb were also on hand for the ceremony, in addition to Annable.

The Irresistible hitmaker is due to give birth next month (Jul13), but she appeared to be in high spirits as she supported the beautiful bride - a source tells Eonline.com, "Jessica seemed in great spirits despite looking like she was ready to burst, though she was definitely touching her belly quite a bit and moving around slowly."

This isn't the first time fashion designer Simpson has participated in a friend's wedding - in December (12) she served as Cobb's maid of honour when she wed actor Donald Faison.