1. The act or instance of leaving one's own bed to go sleep beside one's child, or vice-versa, because the child needs one's company to sleep soundly. A reference to the children's game "musical chairs." We fell into some bad habits when our daughter was about a year old, and we've been playing musical beds with her almost every night for the past three years as a result. Any parent out there knows the sleepy resignation of having to play musical beds at 4 o'clock in the morning.

2. The act or instance of having sex with multiple partners, especially in a short space of time. A reference to the children's game "musical chairs." It seemed like everyone in the dorm rooms was playing musical beds—promiscuity and experimentation was just the name of the game in college.