sow your oats
To lead a promiscuous and self-indulgent lifestyle. Less stylistically, to nail lots of women before you settle down.
Before Frank got married, he spent two years travelling the country sowing his oats. You should sow your oats before you get too old.
Sowing your oats
To get a series of women pregnant over a short space of time.
Kevin - "Did you hear? I got 3 women pregnant last month?"
Bob - "Jeez. You were really sowing your oats"
Bob - "Jeez. You were really sowing your oats"