"Perfect Lover" by Friar Dave (friar_dave@mhbbs.com).
The man is taking a train home to New York in a blizzard, when he is essentially picked up by a beautiful young Swiss woman whom he invites to come home with him. She is intelligent and charming and a veritable sex machine. Literally.
Friar Dave has written numerous excellent stories, and it's always interesting to see where he will go with the next one. This story did not let me down. I'd ruin the story for you if I told you more about where this one goes. All I'll say is that it goes someplace interesting. And the sex is - as usual - hot and nicely described.