Maybe Jessica Simpson should've thought twice before proudly sporting a t-shirt with the "Real Girls Eat Meat" message written on it.

It was just a matter of time before Jessica Simpson's "Real Girls Eat Meat" t-shirt, which might have targeted Tony Romo's vegetarian ex-girlfriend, Carried Underwood, came to PETA's attention.

What may appear as an innocent, witty message written on a shirt, determined the animal rights group to post an entry on its official blog, listing the "top five reasons that only stupid girls brag about eating meat."

Rumors are rife that the 27-year-old starlet, whose singing career isn't going very well, was actually making a dig at American Idol winner and current country chart-topper, Carrie Underwood, who previously dated Simpson's boyfriend, Dallas Cowboys quarterback Tony Romo.

Apparently, she is sick of hearing that Romo might still be having some feelings for Underwood.

"She’s obviously trying to poke fun at her rival and let her know who really has Tony’s heart," an the insider told the Daily Telegraph.

But while Underwood is yet to comment on the whole situation, PETA, which named her "Sexiest Vegetarian" in 2005, quickly jumped to her defense.

"Jessica Simpson's meaty wardrobe malfunction makes us thankful that no one is looking to her for food advice. Chicken-of-the-Sea anyone? The woman who thought that Buffalo 'Wings' came from buffalos would benefit from some good veggie brain food," a rep for the animal rights group said.

Underwood's belief in vegetarianism is so strong, she once said, "If you told me I could never sing again, I'd say that was horrible, but it's not my life. If you told me I could never be around animals again, I would just die."