Kimora Lee Simmons, Djimon Hounsou Separating

Kimora Lee Simmons, Djimon Hounsou Tommaso Boddi/FilmMagic

Kimora Lee Simmons and Djimon Hounsou are calling it quits.

The couple of five and a half years have "officially separated," his rep tells Us Weekly. "Though never married, they have one child together, Kenzo Lee Hounsou, who is three and a half years old."

"There have been quite a few hurtful rumors circulating. The truth is Djimon and I have been separated for some time," Simmons shared in a statement on Twitter Wednesday. "We have remained happy, loving, co-parenting friends and family. We all have much to be thankful for."

The actor and the 37-year-old fashion designer/entrepreneur first began dating in 2007, shortly after she separated from husband Russell Simmons.

Simmons was wed to the Def Jam founder from 1998 until 2006; their divorce was finalized in 2009.

In addition to Kenzo, Simmons is a mom to Ming, 12, and Aoki, 10, with her ex-husband.

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!