Unlike many celebrities, Carrie Underwood doesn't mind revealing intimate details about her love life, especially when it comes to her exes. Take Tony Romo, whom she dated before he hooked up with Jessica Simpson.

"We were both small-town people doing very big things, and we relied on each other, dealing with fame," the calorie-counting country chanteuse, 25, tells the September issue of Allure.

But she downplays the seriousness of the relationship, and hints that she's not quite sure where she and the Dallas Cowboys quarterback stand these days.

"I don't know," admits Carrie. "The phone will ring and it'll be him, and I'll maybe not answer."

(And somewhere, Jessica shines a really bright light in Tony's face and interrogates him about his dialing history.)

And what of her text-message breakup with long-lashed, immaculately coiffed "Gossip Girl" eye candy Chace Crawford?

"We didn't have a fight. No one cheated," she shrugs to the mag. "It plain didn't work."

Then there's that long-ago -- and oft-mentioned -- college romance that left her with trust issues.

"I don't want to name names, even though he probably deserves it, but he fooled around," grumbles the "Before He Cheats" belter. "Oh, yeah, and lied! It was one of those things that everyone knew but me. He was a good liar. Nobody would come out and tell me. And he seemed perfect in every way."

Underwood acknowledges that she's now far more wary of people's motives.

"You never really know why somebody wants to be around you, or if they do genuinely like you," she explains. "I wish everyone had a label on their forehead so you could automatically tell their intentions. Sometimes you just wish that no one wanted anything from you."