Interesting dilemma. What would you do? "Last week I lent a friend a car while her husband was away on a fishing trip. Coincidently, a neighbor's wife was away that week. My car was seen in the neighbor's driveway overnight, easily recognizable because of my kid's college decals plastered on it. A few people have inquired about my car's being there overnight. How do I explain without ratting out my friend?"
Wonder if the couple's are mutually swinging...... Sounds like the best response might be none at all.....