If not parodies, then odd lines thrown in on the spur of the moment. Years ago, after the 1,342nd repitition of "Michael, Row Your Boat Ashore," we threw in: River Jordan is deep and wide, Halelujia,
                      Clean rest rooms on the other side, .....

We also cobbled together a parody of Scotch & Soda specifically because one of our dates - a traditional singer - hated the song so and made such a public issue of it that we dedicated it to her. She loved it!