CaCee Cobb wished Jessica Simpson happy birthday with a hilarious '80s-inspired throwback picture of the best friends via Instagram on Thursday, July 10 Credit: Michael Caulfield/WireImage

That's what friends are for! CaCee Cobb wished newlywed Jessica Simpson a happy birthday by posting an '80s-inspired throwback picture of the best friends via Instagram on Thursday, July 10.

"#tbt and HAPPY BIRTHDAY to my sweets @jessicasimpson. I love you!" Cobb, 36, wrote. In the hilarious snapshot, Simpson has a shoulder-length 'do while Donald Faison's wife is rocking curly big hair. The longtime friends both donned black dresses and slipped on fingerless Madonna-esque lace gloves. (The picture was taken during Ashlee Simpson's 23rd '80s-themed birthday party in October 2007.)

Cobb attended Simpson's nuptials to former NFL player Eric Johnson at San Ysidro Ranch in Montecito, Calif. on July 5, and participated in the rustic-chic ceremony as a bridesmaid. Cobb—Simpson's former assistant—was also a bridesmaid in the singer's 2002 wedding to Nick Lachey.)

Simpson, too, posted a picture of herself earlier today while celebrating her 34th. "And the sun sets on 33," she captioned via Instagram. On her honeymoon, the fresh-faced star shared a beautiful selfie while wearing a brown-and-white chiffon dress.