Taylor Swift Ends the 'Mystery,' Shows Bellybutton in Instagram

Swift snapped the pic while in Hawaii.

— -- Pop superstar Taylor Swift put an end to one mystery today, posting an Instagram pic of herself wearing a swimsuit that revealed her belly button.

Taken in Hawaii, Swift posed with the members of the band Haim.

The "1989" singer had previously told Lucky Magazine she planned on keeping her belly button covered for the time being.

"I don't like showing my belly button. 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," she told Lucky Magazine. "I don't want people to know if I have one or not ... I want that to be a mystery."

No word on how the Haim sisters finally conviced Swift that she could really fully commit to "the midriff thing."