The singer speaks out on her relationship with Tony Romo.

Although they've kept coy about their relationship in the past, JESSICA SIMPSON has come out saying she's in love with TONY ROMO in the new issue of Glamour.

"I'm in love," she says. "Big Time. It's only four months. I can't believe it. It feels like forever. I love this guy."

She says the romance took her by surprise.

"I think it's ironic that I fell in love with a man I thought I would never be interested in because he's an athlete. I was always, an athlete? Heck no."

But now she's even writing music about her new love! Jessica wrote a song titled "Back in my Old Boots" because she says Tony is the one man who made her comfortable just being herself.

For more with Jessica -- including the skinny on her first date with Tony -- check out the new Glamour magazine, on stands May 6.