‘I used to torture frogs when I was young,” the man was telling me, with a stare that would make the most experienced serial killer uneasy. I wasn’t at a Halloween party. It was Friday night in London and I was attending my first singles event. When my friend suggested it, I had expected the evening to be awkward. I hadn’t expected to be nursing a glass of a wine while a stranger described the many brutal ways he had culled the north London amphibian population. After two hours of painful conversation with other guests, we eventually escaped, although not before our new friend leaned in for a bum grope.