Kristin Cavallari, Jay Cutler; What Really Ended Engagement? 1Kristin Cavallari and Jay Cutler may have let jealousy and ego come between them and in an ironic twist her lavish engagement party July 17 with friends may have been the final straw.

Cavallari, 24 was reportedly the one who was dumped. Sources told People that Cutler 28, broke off their engagement, a week after the blow-out party.

They had been dating for 10 months and the Chicago Bears quarterback had even lavished her with a 5.2-carat diamond engagement ring in April.

But Cavallari, best known for best her roles on the former MTV programs “Laguna Beach: The Real Orange County” and spin-off, “The Hills,” may not have been ready to give up on her Hollywood career, or free-wheeling lifestyle.

She also refused or couldn’t shake her close circle of friends and hangers-on who are always determined to cling to a star, while Cutler was used to being the center of attention, just like on the field.

Now those same friends are pointing a finger at Jay.

“Jay Cutler was beyond controlling and didn’t really like Kristin to go out,” a friend tells People.

“When she did go out, he called all the time and demanded to know exactly where she was going and who she was with,” the friend added.

“He made her choose between him and being friends with a lot of her girlfriends. I’m not surprised it didn’t last.”

The former Hills star had been planning a wedding for next spring, and is said to be “absolutely devastated” by the end of her relationship.

Just last week, Cavallari and her friends celebrated at a lavish engagement party.

Cavallari was also reluctant to move on a permanent basis to Chicago, where Jay plays.

Ironically, Cavallari credited the 6’4″ NFL pro with making her feel more confident and improving her body image.

“[Jay] makes me comfortable,” she gushed. “I’ve dated other guys, and I’ve felt like I’m not skinny enough. But with Jay, I’ve always felt really comfortable in my skin.”

Kristin, who recently showed off her sleek physique while walking the runway in a glass bikini at Miami Fashion Week, promised to work out harder before her wedding.

“I’ll probably keep up my regular gym routine for the coming months…until spring,” she says.

“And then probably two months before [the wedding] I’ll go at it harder. Then I’ll probably cut out alcohol for a month or two before my wedding.”

“She was planning her dream wedding, the date was set, the location – everything was set. She’s in shock that the dream wedding she was planning is going to end this way.”