Dog's Underwear Theft Obsession

My dog had a strange obsession with underwear. Every time I hung the laundry on the line, there he was, stealing every pair of underwear he could grab. He'd hide them under the bed, and I'd spend hours searching for them. One time, I even found my brother's underwear buried in the yard. He seemed to have a secret stash. I wasn't sure if I was dealing with a dog or a professional underwear thief.