"Tim has been family for a while now." (Simmons was married to the Def Jam co-founder from 1998 to 2006.
Their divorce was finalized in 2009.) See pics of Kimora's wedding ring.
PHOTOS: Secret celeb weddings Us confirmed that Simmons, 39, and Leissner had secretly wed, after her ex-husband, Russell Simmons, revealed the news via Twitter.
"All of us love @Official Kimora but the fact is she is happily married," the business mogul wrote.
PHOTOS: Friendliest exes in Hollywood Simmons has two teen daughters with her ex: Ming, 14, and Aoki, 12.
PHOTOS: Cutest baby announcements This will be the designer's first child with her second husband, investment banker Tim Leissner, whom she married this past February.
" The author admitted it's not always easy staying on good terms with her exes, but added, "I try to do everything from the viewpoint of what's best for my kids.
I have three kids and two great dads and it's not always easy, but you have to try to be a little selfless and we manage just fine." (Kimora and Hounsou, 48, are parents to son Kenzo, 3.) PHOTOS: Celebrity exes reunited Though the former Baby Phat creative director was recently romantically linked to heavyweight boxer Malik "King" Scott, Kimora insists she's been single since splitting with the actor last year.
Clearly, whoever this mystery man is, he has already deemed himself worthy of hanging out with her nearest and dearest.
He recently took a leave of absence and relocated to Los Angeles.