I love people watching, and I know, hands-down, the strangest thing I've ever seen (and I've seen a lot of strange stuff).
We used to live in a community with a small gym, pool, hot tub, etc. When I would work out, I had a view of the pool and hot tub. I once saw a 40-something Asian man and his probably 12-year-old son soaking in the hot tub, bubbles a rolling, while eating Kentucky Fried chicken directly out of the bucket.