In Italy, a membership card is required for all gay cruise bars and clubs.
Often that is the ARCO (Anddos) or Entes card.
If you don't have the card yet, you can usually acquire it
at the entrance of the venues that require the card (5-17 €).
When you acquire the card you need to show your photo ID,
after that you only need the membership card.
Gay leather club association, organizing or supporting various special events (check their website), for instance the annual leather and fetish event Fetish Pride Italy in December.