In a game of cards to overplay your hand is to bet on your cards with misplaced confidence. Figuratively, to overplay your hand means to ruin your chances of success by being overconfident. This is a popular idiom in social and professional contexts.

1. I thought Ruth wanted my honest opinion on her performance, but she hasn't spoken to me since. Now I think I might have overplayed my hand.
2. I might have overplayed my hand when I asked Fiona on a date.

1. I overplayed my hand by demanding a pay rise. Now I'm worried that I might lose my job!
2. Don't overplay your hand in these negotiations. We need this deal just as much as they do.