We have stated before no to single males replying to our ad as we know there will be the single male at any site we visit - we are just a showing couple so don't require anyone else to join in. The request that we have made for other couples is so that we aren't just the only ones there. We have spoken to single males in the chat room and they know where we are.
What I'm tryin to say is that surely it's in the best interests of the single males to know that couples want other couples there too.