I'm surprised this hasn't been updated in a year* but here is the rumored synopses for the movie......which sounds terrible.
"Remy Lebeau (Channing Tatum) is on trial in New Orleans. He’s considered a huge security risk. We flashback to almost 25 years before. Master thief Luke Lebeau runs into eight-year-old Gambit while doing a heist. Impressed by his skills, he offers to take the mutant orphan under his wings. Raised alongside other strays he calls “cousins”, the teenage Gambit becomes the superstar of the Thief Guild. He encounters Bella Donna Boudreaux while on the run from the police. Sparks immediately fly since Bella is also a fellow mutant. Their love is directly prohibited by both families since the Boudreaux are sworn enemies of the Lebeau clan. Deciding to unite the two sides, Remy offers to have the two clans team up on a HUGE heist to profit both families. Of course, the whole plan goes awry, and in the chaos, Maryanne Boudreaux shoots and kill Luke Lebeau.
We jump to 10 years later; Gambit is hired to do a job in Paris to steal something from the Louvre Museum. It was apparently a test job to see if he still has it. His mysterious employer is revealed to be Nathaniel Essex a.k.a. Mr. Sinister. He offers Gambit 40 million to recover a mysterious trunk that was stolen by the Boudreaux clan. It will be auctioned off during the yearly Thieves Ball where all the criminal organizations in the world meet up. It uses New Orleans’ Mardi Gras celebrations as a cover. Gambit decides to enlist a crew of mutants to pull off this seemingly impossible heist…"
*no I'm not