cavallari111910_01_split.jpgKristin Cavallari has called off her engagement to Chicago Bears quarterback Jay Cutler after just ten months together.

The couple were planning a spring wedding after he proposed during an April vacation in Mexico. In fact, just a week ago, Cavallari Tweeted about her engagement party: "Thx to all my amazing friends for making my engagement party a blast last night! as did Cutler: "Thx to all my amazing friends for making my engagement party a blast last night!"

Turns out, the couple may have been suffering from annoying family squabbles between their parents. A source tells X17online exclusively: "Jay and his family were making fun of Kristin's dad's height a lot, and she got sick of it. That combined with a few other compatibility issues, lead them to break off the engagement."

Kristin was out with pals last night at The Beverly and was reportedly chatting with pals Nicky Hilton and Alessandra Ambrosio about how she and Jay had called off the wedding. The Hills star's engagement ring was also missing ...