The cat did it!
I have seen my cats do some interesting things. I have a cat who "high Fives", usually when he wants something. This cat got his owner in trouble with the girlfriend
His girlfriend found a pair of women's underwear in the bed, that were not hers. The boyfriend said "I have no idea where they came from? Turns out the cat was stealing clothes from the neighbors laundry that was on the line and in a basket in the backyard.
Here's the story