Spot on, what those guys said.
Don’t be afraid to email them with any questions or worries you have.
You’ll find that most people are really friendly so just go in with and open mind, ready to socialise but knowing your own boundaries. Just enjoy the experience together and don’t rush into anything.
Carry on communicating throughout the evening so you are aware of how each other is feeling.
Be confident and feel good in whatever you choose to wear - you can’t go wrong with a LBD and maybe bring a sexy piece of lingerie to change into if you’re feeling super brave 
Here’s my post that I think @DanceswithPenguins was referring to:
We’ve now been to a handful of clubs and really enjoy the atmosphere although we only really play with each other when we visit - we use the time to meet new people, socialise and establish any connections with other couples x