This joke has a little history behind it.
Back in the 1960's in Chicago there was a radio station (WLS?) with a very popular disk jockey named Dick Biondi who told this joke on the air and got fired for it the very same day.
A newlywed couple who were both avid baseball fans attended a game at Sox park. They were still on their honeymoon and very affectionate, hugging and kissing so much that they weren't able to follow the game. After a couple of seconds of thought the wife says, "I've got an idea, honey. You kiss me on the strikes and I'll kiss you on the balls."
[Note - reportedly a cute, but false story - ed.]