Diaper changing etiquette?

Angela
My brother and sister in law have a habit of changing my nephew in front of everyone with no changing pad or towel underneath him. This happens on the couch, chairs at restaurants, and on my brand new rug last weekend. My nephew is about to turn 3, so this has been going on for quite a while. Last weekend, my husband finally couldn't bite his tongue anymore when they had my nephew spread his cheeks to wipe his poopy butt. They seemed offended and said we'll understand after our daughter is born. Still, I can't imagine changing her like that! Is this weird? Are we being too sensitive? Not sure how to handle this situation...