July 11 (UPI) -- Jessica Simpson rang in her 37th birthday by posting a topless photo online.
The singer and designer shared a picture of herself relaxing in a pool Monday before stepping out with friends for her birthday dinner.
"Kiss My Butt 36," she captioned the snapshot for her 3.8 million Instagram followers.
"Happy Birthday to my first true love @jessicasimpson," Cobb wrote. "I love you for better or worse, til death do we part."
"This world is a better place because you are in it," Ashlee captioned a photo of herself with Simpson. "I adore your heart, your kindness, your love, and ever cool existence. I have been so blessed to have the most amazing big sis, and I love you mom for having us both. Happy birthday my beautiful Sis. I LOVE YOU!!!!!"
Simpson and her husband, retired NFL star Eric Johnson, celebrated son Ace's fourth birthday at a Moana-themed party last week. The couple also share 5-year-old daughter Maxwell, but are not planning on having more children.
"I have two beautiful children and I'm not having a third. They're too cute. You really can't top that," she explained.