Hot U.s. pop trio The Jonas Brothers have vowed to stay virgins until they wed.

The three brothers, Kevin, Joe, and Nick Jonas, have revealed they've sworn a vow of purity to each other.

Joe, 18, says, "(We've made) promises to ourselves and to God that we'll stay pure till marriage."

The trio all wear purity rings to remind them of their pledge.

Nick, 15, who previously dated Miley Cyrus, tells Details magazine, "I got mine made at Disney World. It's pretty awesome."