finders keepers (losers weepers)
From Longman Dictionary of Contemporary Englishfinders keepers (losers weepers)finders keepers (losers weepers)spoken used to say that if someone finds something, they have the right to keep it → finderExamples from the Corpusfinders keepers (losers weepers)• And it's finders keepers, y'know.• The rule for such races is simple: finders keepers.