LOLOLOL He doesn't even do it with purpose! He just keeps betting until he's got nothing left to bet, and Arthur's got a stack of IOUs and promises to bring him coffee every morning for the next month--no matter what part of the world Arthur may be in at the time--and Eames has already handed over his watch and his shirt only to see Arthur set it on fire, but he cannot let this stand. He has to figure out Arthur's tick, his tell. It is not possible for him to not have one at all. So, you know, he bets the only thing he'd got left.

Arthur raises an eyebrow, and smirks, and calls.