J.Lo & Backup Dancer/BF All Smiles On Road Trip

11/14/2011 6:30 AM PST

Jennifer Lopez -- First Photo with Dancer Boyfriend Casper Smart

TMZ has obtained a photo of Jennifer Lopez with her new BF -- and backup dancer -- Casper Smart ... taken while they were traveling in Europe. 

According to our sources, Lopez and Smart spent the first few months as "just friends" -- flirting, talking and just hanging out -- but lately they've been touchy-feely in front of JLo's other dancers. 

We're told the mood of rehearsals has shifted -- she's a lot more focused on Casper ... who is 24. Jennifer is 42. 

The photo was snapped in the summer when JLo was in Ukraine for a performance. Casper danced in the show, but we're told they were not dating at the time.

Jennifer's rep hasn't gotten back to us.