It's rude to take back a gift you've already given.
Kim bought Tim a lotto ticket for Tim's birthday, who scratches it off and wins $10,000.
Kim wants to finish her buisness with Tim.
Kim congratulates Tim, since she knows the moment she gave the ticket to Tim it's no longer hers.
Kim says that since she paid for it that it's her ticket, so she takes it.
Tim is pleased with winning and glad Kim gave him such a great gift.
All of Kim's friends including Tim now despise Kim for taking the ticket back.