Dear Prudence,
When my in-laws stayed with me and my husband for a week (this was their first such visit), I learned something disgusting about my mother-in-law.
She does not adequately wipe her butt. While doing the laundry, I discovered prominent skid marks on all of her underwear. I was thoroughly grossed out. What’s a tactful way of addressing this with her for the next time she and my father-in-law are over?