Nick Loeb and Sofia Vergara
05/10/2012 at 07:00 PM EDT
From the outside, Sofia Vergara
and boyfriend Nick Loeb – who have reportedly split – seemed to be in it for the long haul.
The vivacious Modern Family
star remained a constant by Loeb's hospital bedside
as he recovered from a serious car accident
in Aug. 2010. A year after the injury, Vergara also stood by her man when he considered running
for the Florida U.S. Senate.
But behind the public appearances and PDA was an argumentative pair of opposites, who sources say had incredible chemistry, but were plagued by problems from day one.
One source close to Vergara's inner circle, who tells PEOPLE the couple have broken up and gotten back together "over a million times," calls their recent split, "a relief."
"It was never a good match," the insider says. "She is fiery and free-spirited and wants to enjoy life to the fullest by traveling and going to parties and events. He's very concerned with his businesses, political aspirations and ultimately settling down."
Reps for both Vergara and Loeb had no comment.
Approaching 40, Vergara – who was married at 18 and had a son when she was 20 – has no current desire to tie the knot again or have more children. Loeb, on the other hand is what another friend describes as "very persistent almost to the point of annoying" about starting a family with the actress.
The source, who has known Loeb, 36, for years says his "overbearing, smothering" ways are another likely cause for the split.
A third source adds, "[Sofia] is happy with her life the way it is. If she ever did change her mind, it would be because he wanted all of this."
And although Vergara seemed like the storybook example of a supportive significant other, when it came to Loeb's political aspirations, much of her happiness was an act.
"Nick put off his run for Senate because he [loved] Sofia and she didn't think it was a good idea at this time," the third source says. "[She] said it was because he was not fully healed from his accident. But in truth, she is sitting pretty in Hollywood and doesn't want to be a political wife right now."
At a Florida press conference Loeb held in November to announce he would not run for Senate, Vergara appeared like the ever-supportive partner as she joined her beau, but behind the scenes the situation was ugly.
"They fought because Nick had assumed too many things and Sofia was not ready for any commitment – love or political," the source says. "It was a bad scene."
But it doesn't sound like either of the two will have trouble finding someone new.
Vergara's spicy, confident attitude and sex appeal has made her one of the most talked about television actresses of the moment. And as for Loeb, the third source says he "has so many women after him that he won't have trouble starting over."
Additional Reporting by KATE COYNE and LINDA MARX