swindler, n.All

Swindler (n.) is ⁠​‌​​​‌​​​‌​‌‌​​​​‌​‌​​‌‌​‌​​‌​​​​​‌‌​​‌​​​‌‌​‌‌​⁠worse than a rule-breaker: he does not transgress the rules but pretends to keep playing when he has already left the game.