After nearly three years together, Reese Witherspoon and Jake Gyllenhaal called it quits in early December. "It broke his heart," an insider reveals in the new issue of Us Weekly.
A source close to Gyllenhaal, 29, explains that the once-golden couple "fought constantly in the past few months," and that the relationship concluded over a series of phone calls.
Adds another source, "No one cheated. There was no drama."
After the pair met on the set of the film Rendition, their romance began in March 2007 -- when Witherspoon, now 33, was still smarting from her 2006 divorce from husband of seven years Ryan Phillippe, 35, with whom she has two children (Ava, 10, and Deacon, 6). Indeed, sources say that her divorce and her kids were the two driving factors in the split.
"She felt pressured to wed again but she wasn't ready," an insider says. "She couldn't give Jake enough and she got cold feet. Jake wanted all of her."
Although Gyllenhaal moved into her $5 million home in June 2008, Witherspoon struggled to quell her doubts about his suitability as a stepfather and long-term partner. "She really worried that they didn't have enough in common," the pal says.
As a hands-on Mom, the "super-type A" actress also fretted over losing time with her kids to her boyfriend. "When she was giving all of her energy to Jake, she felt like she wasn't giving her kids enough," the source says.
Not that Gyllenhaal didn't try with Ava and Deacon, the insider points out: "He was great with the kids, but she felt like he didn't get the whole scope of what that entailed."
To find out how the breakup might affect Witherspoon's kids, how her ex-husband Ryan Phillippe is faring with new love Abbie Cornish, and to look back on their whirlwind romance, pick up the new issue of Us Weekly -- on newsstands now!