Exclusive: Joe Jonas Wants Taylor Swift Back

Joe's jonesin' for Taylor again.

Once-acrimonious exes Joe Jonas and Taylor Swift are back in contact, multiple sources tell the new Us Weekly, out now -- and Jonas, 22, is eager to restart the romance he ended with a 27-second phone call in late 2008.

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"He wants her back," a Jonas source tells Us. "He wants to show her he's a changed man and would love to see what's possible between them."

To that end, Jonas and Swift are "testing the waters" as platonic pals for now. Jonas was even a surprise audience member at Swift's sold-out Sept. 1 concert in San Jose, Calif.

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Post-split, Jonas and Swift, 21, infamously traded barbs about one another via song. Swift rehashed the breakup in "Forever and Always" and trashed his rebound, Camilla Belle, in "Better Than Revenge." Jonas ranted about "superstars and all the tears on her guitar" in his track "Much Better."

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But those bitter musical sentiments are water under the bridge now, pals say.

"They're putting their past behind them," a Swift source explains. "And maybe rekindling an old flame."

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For much more details on this unexpected love rematch -- how Taylor's responded so far, how she invited him to her concert and more -- pick up the new Us Weekly, on stands Friday.