When we first started we were looking for a SF as well... and... well we found a female partner but she just happened to have this nice husband who understood it was our first go round and was willing to watch us play together with his wife. That lasted for our first get together... but after that we realized that it felt good and right for us to bring another person (male) into the picture... and we've never looked back. I can't believe we ever considered not doing a couple thing...
Just my input... keep looking... keep talking... keep your options open!
Mrs WA