wild oats

The youthful rebelliousness or promiscuity that one partakes in before settling down. Most commonly used in the phrase "sow (one's) wild oats." Bill and I had to break up because I was looking to get married, and he just wanted to sow his wild oats! You can't sow your wild oats forever! Soon, you'll want a wife and a house, and you'll regret the things you're doing now.