Jennifer Lopez, Casper Smart ... They NEVER Broke Up!!!

Jennifer Lopez and Casper Smart did NOT get back together, because we found out they were never really apart.

Sources close to the couple tell us ... the break-up they announced in June was a business move. Multiple sources say in the spring they did stop seeing each other, but only for a few weeks.

We're told JLo was hawking her movie, "Boy Next Door," and honchos on the film felt creating a buzz that she was hooking up with co-star Ryan Guzman would help sell tickets. It's hard to do that when you're not single.

But the decision wasn't one-sided. We're told Casper was up to the same thing because he was shooting "Street," a UFC fighter movie where he buffed up. Again, he was more appealing single.

It all makes sense now. Two months after they revealed their break-up, a photog got shots of them in a convertible BMW. When JLo saw the photog, Casper put the top up and she slumped down in the passenger seat, out of sight.

Then in December, a dog at Jennifer's house bit a neighbor. Turns out it was Casper's dog that did the deed and he came running out of the house in his pajama bottoms after the attack.

In February, Casper went to a GQ event, and when he left he walked down the block and jumped in a car JLo was driving, avoiding photogs. A few minutes later a photog saw them walk into a restaurant together. When they saw the guy they hightailed it inside.

And then they got bolder, dancing together at a Big Sean concert at the House of Blues in WeHo.

Case closed.