The sexual act in which a man performs on a woman (preferably someone's mother). First all the lights are turned off for total darkness. Next the man slips a glow-in-the-dark condom over his penis and then begins to float around the dark room; thus giving the effect of a flying spaceship, or other un-identified floating object. The woman then is invited to catch such object with whatever she pleases, i.e. her mouth or other orifices. When the man grows weary of floating around, he then proceeds to crash-land his "ship" into the woman's "Area51”.
"Hey Mitch, I totally UFO 'd your mom last night ! "
In reference to the skiing and snowboarding industry, UFO stands for uncoordinated fucking orient. Applies to all the asian, indian etc. punters who cant ski or board worth a damn and will never be able to - why? Because they are a UFO.