For men: "I had a running discharge from my genital organ* so I had to sequester myself. My day of atonement (after sacrificing two turtledoves or two young pigeons) isn't until the day after the Memorial. Leviticus 15"
Adaptation for women: "I am having a running discharge of my blood flowing* many days when it is not the regular time of my menstrual impurity. I counted 7 days and caught myself 2 pigeons. On the 8th day I met Elder Jones in the parking lot of the hall and asked him to sacrifice them for me. He said no, so I am still viewed as unclean. That means I can't even sit on the chairs in the hall or touch the vessels as they are passed during the Memorial, or I will make them unclean too. Leviticus 15"
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*Now here you really need to take some creative license. Be gross. Be graphic. Talk about the color, consistency, smell, burning sensation, cramps, rashes, etc.