It's  NOT over between Justin Bieber and Selena  Gomez ... sources very familiar with the situation tell TMZ.

Two  Things.

Thing 1: Justin is not involved with anyone  else. There are pics of Justin with a Victoria's Secret model circulating, but  there's nothing there.

Thing 2: Justin would like to get  back with Selena, and thinks it can happen. We're told the way Justin sees it  ... they've broken up a bunch of times before and this is just another blip.

We're told he's not freaked out ... he thinks there's a good chance  they'll make up. 

Ah young, very rich love.