creepy uncle adj. n.:
A person, who through their actions and/or words, causes unease to others (male or female) by unnessesary or gratuitous sexual advances.
"That man was getting all creepy uncle on me."
"Larry is sure a creepy uncle."
when a gentleman secretly masterbates while the female partner is asleep in bed, using her ass, face or just overall naked body for mind material to help ejaculate.
Last night, this girl passed out naked in my bed so I gave her the creepy uncle and wiped my hands on her socks.