Justin Timberlake and Jessica Biel’s decision “to part ways” after four years together came as no surprise to friends who say  the “SexyBack” singer checked out of the relationship long before the March 10 announcement. OK! takes a look at the inside scoop in this week's issue!

OK! NEWS:  JESSICA BIEL & JUSTIN TIMBERLAKE’S REP CONFIRM SPLIT!

“He has been aching to move on for months,” a source close to Justin tells OK!. “Justin and Jessica have been going in different directions for a while,” adds a family friend, who says that despite 29-year-old Jessica’s desire to marry, Justin, 30, “isn’t ready to settle down.”

OK! NEWS:  JUSTIN TIMBERLAKE HEADED TO HARVARD

Friends are comparing Justin’s breakup with the A-Team actress to his January 2007 split with Cameron Diaz. After refusing to commit to Cameron after four years together, Justin moved on quickly to Jessica. “He usually does have someone he can turn to when he breaks up,” confirms the family friend.

OK! NEWS: JESSICA BIEL STEPS OUT IN LA POST SPLIT WITH JUSTIN TIMBERLAKE

This time, friends say that someone is newly single Mila Kunis, 27, who became close to Justin while filming Friends With Benefits last summer and recently ended her eight-year relationship with Macaulay Culkin. Though some insiders say it’s already on, one pal tells OK! they're just friends with "great chemistry."

OK! GALLERY: MILA & JUSTIN ARE GOOFY FRIENDS WITH BENEFITS ON SET

“Justin and Mila have been talking and texting each other,” confirms the source. Reunited on Feb. 27 when they presented an award together at the Oscars, the pair flirted up a storm backstage. “Justin couldn’t stop touching Mila, and she was giggling like a schoolgirl,” an eyewitness tells OK!.

FOR MORE ON JUSTIN AND JESSICA POST BREAK-UP, PICK UP THIS WEEK'S ISSUE OF OK! — ON SALE EVERYWHERE NOW!