In US traditionally the draw is a result that does not satisfy either of the two teams.
This expression comes from Navy coach Eddie Erdelatz in 1953, when he came up with this classic definition for a tie football game while describing a scoreless tie between Navy and Duke. The coach did not explain this metaphor, but it is possible to think about a kiss like a good thing (the victory), and kissing one's sister takes away the good to this gesture.
