Are Gwyneth Paltrow & Madonna Feuding?

Gwyneth Paltrow has some advice for her friends: Don't cross her!

"I can be mean," the Oscar-winning actress tells Vogue. "I can ice people out and I can definitely harbour revenge. In fact, I'm having a situation right now with a friend where I'm feeling pretty angry. But revenge is corrosive and it doesn't make me feel good."

In the same article, Gwyneth takes a dig at her pal Madonna, prompting speculation that the two are feuding. Gwyneth and Madonna shared the same trainer, Tracy Anderson, but now Tracy is Gwyneth's business partner.

"Yeah, it's good that [Tracy] doesn't train Madonna any more. It was too much. She keeps people waiting — it takes up your whole day," Gwyn sniped.

The 37-year-old actress and mother of two is opening her own exercise studio in London based on Tracy's teachings. Gwyn claims, "I can eat what I want, as long as I exercise, which is just as well, because if I put the word 'diet' into my brain, I immediately gain a stone."