Two of the best poker players in the world are at odds with each other over a bet that could force one to pay the other $1.8 million.

Monday night, Jason Mercier won a tournament at the World Series of Poker for $273,000 and a gold bracelet. Even though Mercier is popular with fans, many of his fellow pros were not happy for him.

Why? Because Mercier engaged in massive "bracelet" bets that he told CNBC earned him "in the neighborhood of three-quarters of a million dollars," more. He bet several other players at 3-to-1 odds, against him winning a bracelet this summer. But it was another, similar bet he made, that has the whole poker world talking.

On Wednesday, Mercier finished second in another tournament, coming up just shy in his bid to win a second bracelet, which would have been bad news for fellow pro Vanessa Selbst. And that's where the controversy comes in.

Mercier and Selbst, both sponsored by PokerStars, which is owned by Amaya, were at a poker tournament series in the Bahamas in January. Alcohol was involved, though how much depends on who you talk to. Mercier and Selbst made a bet. Selbst gave Mercier 180-to-1 odds that he could not win 3 tournaments at the World Series of Poker. Mercier immediately paid her $10,000, hoping he would accomplish that difficult feat and get paid $1.8M.

Wednesday afternoon, when Mercier was still on the verge of winning his second bracelet, Selbst said on Twitter that she was extremely drunk when she made the bet and tried to buy out of it the next day for $1,000. And she offered Mercier $100,000 to let her out of the bet. But Mercier refused.

Mercier responded to Twitter criticism with "LOL at the friend aspect of this whole thing…It's called taking #Responsibility"

Wednesday night, after the disappointment of coming so close and failing to win, with so much on the line, Mercier hopped right into another tournament.

After all, he still has two more bracelets and $1.8 million to win.