Who of the Jonas Brothers already found a girl?

No they are all currently single.

Joe used to go out with Mandy, at another time it was A.J. Mickalka. Demi Lovato likes him though.

Nick was recently going out with Miley Cyrus and it's rumored that he's now going out with Selena Gomez despite the fact that he isn't and he's said he isn't.

I'm even sure about Kevin anymore I can't tell rumor from fact about him anymore.