As I have had many crappy life moments, I have thankfully never dealt with this. I have never been to London metro area, but I assume there is quite a few hundred/thousand different pubs/clubs out there, I would seriously look for an alternative, this will escalate before it gets better. As a teen I was constantly hearing gay slurs, I was straight, it wasn't until I lost weight and wore nice clothes that I heard these comments, when I was overweight and dressed in with t-shirts and jeans I was laughed at due to weight or poor sloppy clothes. They are looking for something, they spot something different and look for a bullying tactic, they won't be arrested or face punishment.