TBH in my experience Saunas are pretty much all guys. You might try a bi event at a club...all the clubs round me have them (although I haven't been myself)

We've been planning to go to the Warehouse project for years and never seemed to find the time....fingers crossed it appears again

I would agree about the sauna. I have had both Male and female partners. When I started looking for new male friends (with Mrs' knowledge) I tried sites like this but always got cold feet. 

My local sauna was a low stress and relaxing environment. In my experience attendees are understanding and respect boundaries (even if they change mid play). I have  been several times and done nothing at all apart from having a steam and watching some porn. Equally I've been and gone all the way. It's up to you.

So H and I are returning to the hard house and techno of our youth and are looking for a party or club night in London or the North that mixes dancing with our taste for sex with others. Any suggestions. 

Kink clubs would be fine - we were going to go to Torture Garden but the timing doesn't work.