For something completely different for the back end of Boxing Day, how about another Boxing Day Lock-in at The Vanilla Alternative? This relaxed and laid back event is only open to couples and single ladies (together with a few invited single guys). Although in above posts it mentions 'Entry price for members', anyone registering their details (for free) online via the club's website is automatically a 'member'. Anyone visiting for the first time will need photo ID.
It's an early start at 7pm and doors will only be open from 7 to 9. The fun continues until everyone's had enough! At the time of writing this, a few onsite hotel bedrooms are still available if anyone wants to stay over.