the stubbly chin
This is the action of shaving your balls and letting them grow back to a stubbly stage, and as such, while a sexual partner (or victim of any kind) is asleep or passed out, you proceed to scrape your stubbly bollocks across their chin
'That girl was so drunk last night'
'I know, she passed out, so I gave her the stubbly chin!
'I know, she passed out, so I gave her the stubbly chin!