I know this is really old but some might not have heard it:
For their golden anniversary a couple decides to repeat their honeymoon trip. They drive to the Poconos and find the same romantic lodge is still there. A vibrant young couple, clearly very much in love, is checking in when they arrive. The husband says "I'll just nip around by their window and see what they do -- we can maybe get some ideas to spice up our 50th year!"
Sure enough, through a crack in the curtains he sees the young couple engaged in foreplay. They are naked, sitting on the floor some distance apart with their legs spread. The young man is shooting marbles, aiming to lodge them between her vertical lips; she is tossing doughnuts, aiming to ring them around his erect member. After a few minutes of this they rush together and make tumultuous love.
The old man is quite excited by this idea, and makes his way back to his eagerly waiting wife. He describes the game, his wife getting more and more inflamed herself. "Darling, this is going to be so good," she says:"Run right out for some grapefruits and lifesavers!"