U Haul
Humorous term to describe a Lesbian who is always in love, out of love..
u
UC
the status of a person's penis, in that it is uncircumcised
UFOs
An acronym for the term "Unbelievably Fantastic Orgasm".
Uncle Frank
slang for someone who is masturbating.
Uncut Cock
An uncut cock is another term for an uncircumcised penis. That means that the penis has not been circumcised, so it still has the foreskin.
Underwear Fetish
An underwear fetish is a sexual attraction to underwear or to men wearing underwear. Some men have a fetish for a particular type of underwear, like boxers or briefs.
Underworld
19th Century euphemism for a woman's genitalia and the vagina.
Unload
Common slang term for when a male ejaculates, usually a large amount of semen.
Unruly Member
British term, referring to the Penis.
Urethral Play
A form of sexual play, where a tube or device is inserted into the penis, and either left, or further inserted into the bladder, for a more advanced form of piss play.
Urolagnia
The attraction for urine, for being urinated on, urinating on, or consuming urine.