I've always wanted to get one, and when they say something about my life line I want to pull out a knife and say "We'll see about that" and start laughing like a maniac.
@Aaron You'd think, but it doesn't. It is also easier to find men than women. So mff is harder to make happen than mmf. mfmf is still easier than the other two, which is surprising.
@Aaron You don't need to be. You can switch back and forth or work at both ends. Don't worry about equal pleasure, there would be plenty in it for you.
@Metool I should say, I couldn't start one without having met the other person. But that certainly sounds better. I hope you two work out as well in person. :)