It was a balmy mid-summer’s Friday evening, and a local band booked to play at the pub down the road meant the place was packed. My partner, Tom, and I had gone to meet up with a few friends, some girls I knew from work and a guy called David, who originally was an old friend of Tom’s who we’d recently reconnected with. The drinks were flowing and we were all having a great time. Although we didn’t end up paying much atte...