2. a man that doesn't act his age, especially in social situations with the opposite sex
3. a man that is incapable of performing the most menial tasks
Wife: Stop being such a penile rivulet and do your own goddamn laundry from now on!
"Maybe if you weren't acting like such a penile rivulet, you could have banged that chick."
Office Worker: How do I turn on the copy machine?
Co-Worker: What are you? A penile rivulet?