As one of the most famous pop stars on the planet, Taylor Swift likely has to work overtime to keep certain details of her personal life private from the public. However, there's one aspect about Taylor that she has done an excellent job at keeping a mystery: her belly button.

In a new interview with Lucky magazine, Swift revealed why she has never been photographed with her belly button showing, despite her recent habit of partaking in the cut-off top trend. So, what's the deal Tay Tay?

"I don't like showing my belly button," the 24-year-old "Blank Space" songstress told Lucky in its December issue. "When you start showing your belly button then you're really committing to the midriff thing. I only partially commit to the midriff thing-you're only seeing lower rib cage. I don't want people to know if I have one or not."

Swift's last statement actually echoes what some fans have speculated. In fact, several Internet conspiracy theorists have wondered if the "1989" singer is hiding the fact that she doesn't have a belly button and is secretly an alien.

Because that's the logical conclusion, right?

Still, Swift has no problem with fans making up their own theories about that part of her stomach.

"I want that to be a mystery. As far as anyone knows based on my public appearances, they haven't seen evidence of a belly button," said Swift. "It could be pierced. They have no idea. If I'm going to get some sort of massive tattoo, it's going to be right next to my belly button because no one's ever going to see that."

We're guessing Swift devotees will be on the look out for a peek at the singer's tummy for a long while. Good thing it's now sweater weather.