Selena Gomez and Justin Bieber have had their problems over the fall, but not they're back on again. But, Selena is upset about Justin's new friendship - with her ex-boyfriend Nick Jonas! "Justin and Nick Jonas hung out all night", says a source. "Selena was crying about it. He wouldn't even return her calls when she found out and called him up". We think Selena has nothing to worry about, and we hope they will be ok!