Study in Luck by Ken Poyner

An old drive-in, with the sound box unclipped from a pole and hung inside the car window by the same clip.  Bodies sitting close as on the huge screen massive images move like elephants in love.  Bodies sitting close is the important element:  the car a mobile motel room with the excuse of a movie.  Might as well rent a room and pretend you are there just to watch the television together.  There you could get more naked.  But no one at the drive-in cares how naked you get.  The movie runs on, every couple is preoccupied with each other’s hands.   Then, just like last week, the intergalactic portal opens in your back seat and the Zorgarin researcher suspends himself two inches above the faux leather bench seat, staring at the two of you entangled in the front.  You ignore him, as your hand is about to go slithering skin to skin.  He has seen this movie before, but nonetheless he pulls out his service recorder and starts taking field notes.