A position of sexual intercourse in which the penetrated partner ("bottom") lies on his/her back on the bed, body perpendicular to the edge, with his/her legs splayed at a broad angle, while the penetrating partner ("top") spreads his/her legs until s/he is able to penetrate comfortably and then lays on top of the bottom. Named for the mechanism that supposedly converted X-Wing fighters into attack position in Star Wars.
We did it in the S-Foil position until I got tired, then we did it doggy style until I shot like a fire hydrant on her back. My knees hurt, now.
by BigMike31489 May 29, 2011