Dear Care and Feeding: I banned my nephews from my daughter’s birthday party. I’m done playing nice.

Care and Feeding is Slate’s parenting advice column. Have a question for Care and Feeding? Submit it here .

Dear Care and Feeding,

My sister, “Yasna,” has two boys who are 4 and 6. They both have a disgusting and unsanitary habit that neither she nor her husband has made any effort to curb: They pick their noses and wipe whatever they extract on anything that happens to be handy. The excuse Yasna and my brother-in-law give is that it “comes right off.”

When they visited this past May for my son’s First Communion party, my husband and I found boogers wiped all over the door moldings after everyone had left. By the time we found them, the snot had dried. Although we cleaned it up, it left stains on the wood.

My daughter is turning 4 next month, and I’ve decided not to invi