ball's in your court, the

the ball is in (one's) court

One has the responsibility for further action, especially after someone else previously held responsibility. The phrase originated in tennis. Well, they invited you, so the ball is in your court now. Do you want to go out with them or not?
See also: ball, court

ball's in your court, the

It's your responsibility now; it's up to you. For example, I've done all I can; now the ball's in your court. This term comes from tennis, where it means it is the opponent's turn to serve or return the ball, and has been transferred to other activities. [Second half of 1900s]