Muddy Glove

During intercourse, the man reaches inside the anal cavity of the woman and proceeds masturbate using the rectum of the woman as a glove.

I did the old muddy glove on the wife for our 60th wedding anniversary; I was picking corn out of my finger nails for hours.

Corn-chaining

Eating undigested corn from faeces, then repeating this process in a chain of different people until said corn is digested.

A: I think I'm just going to do some corn-chaining with the family this weekend.
B: Nice. I had a 7-man corn-chain going last month.