He’s Not the Milkman. He’s the Milk Guy.

Photo: Brian Finke

One evening in February, I received a text: “It’s the Milk Guy.”

A moment later, my phone rang. The man on the line — whom I’d found on a sketchy website recommended to me by an influencer in Tribeca — set up a time to meet. A few days later, I watched from my stoop in Williamsburg as a green van pulled up in front of the church across the street. The Milk Guy sported a skullcap and smelled faintly of cigarettes. He was not the frat boy I bought weed from in college; no...