The act of ejaculating so hard in one's face that the sheer recoil of the
busted load makes the receiver's
head jerk back then to the side (either side will do) much
like the unfortunate assassinated U.S. President of the 60's.
Man: You ready for it baby?
Woman:
Yea gimme your man-chowder
Man: UGGHHHH! *shoots his
load and does
the J.F.K.*
Woman: WTF was that?
Man: That...*tiredly* was your first J.F.K.