Jessica Simpson’s Crank Calling Kristin Cavallari!

It seems that although Nick is no longer dating Kristin Cavallari, Jessica Simpson (his soon-to-be ex-wife) is still quite worked up over the fact that she was part of his life.

Nick Lachey meanwhile has allegedly found himself a new girlfriend, American TV host Vanessa Minnillo. The pair were spotted "getting hot and heavy" in New York earlier this week, and didn't seem to care who saw them. "I saw tongues on skin," tells an onlooker at Underbar. And it appears the incident wasn't just a one-night fling, Nicky and Vanessa dined together the following evening, too.

According to Star Magazine, Jessica got especially upset after she saw her photo right next to Kristin’s in a magazine, says the source.

“She was furious. She thought it was insulting and embarrassing to be lumped together with Kristin! As far as Jessica is concerned, Kristin’s a nobody -19 year old reality tv star who has just been using nick for free publicity.�

In no time, “Jessica got hold of Kristin’s cell-phone number and got a real kick out of making crank calls to it.�

Though a rep for Jess denies the story, the source claims: “She’ll ring Kristin up and just say nothing or try to order pizza or Chinese food and talk in different accents! She’s even gotten some of her friends in on it. The pranks are harmless, but I think Jessica likes knowing that she’s irritating Kristin in some way.�