sow one's wild oats
Definition from Wiktionary, the free dictionary
- (idiomatic, of a male) To spread one's genes around by impregnating many females.
- (idiomatic, of a male or female) To engage in premarital or extramarital flings.
- (idiomatic, of a male or female) To have numerous sexual partners.
- (idiomatic, often of young adults or the recently divorced) To indulge in a period of irresponsible behavior.
to spend a period of one's youth behaving irresponsibly