What I prefer is another married or committed women where her husband is fully aware of the situation.

Same here, I would do a three-way with my wife and another woman (a MFF), in fact we have one lined up for the very near future, but I'd rather my wife have all the fun with her, I'll pitch in as requested. But even the mere thought of swapping with another married couple, man, that's getting me going just thinking about it as I type this sentence! We've done separate rooms so I was alone with the wife, doesn't matter to me if it's same room or not as long as I know my wife is safe and having fun, but yeah, I do prefer sex with a married woman. Not quite sure why, not that it matters.

But always be honest, just put on your profile that you are looking for MFM's with married or committed couples, and put down what your wife is interested in and have plenty of pictures with both you and your wife. Have pictures not just of you having sex, but several just out and about in public so others can plainly see you're not lying, you really are married and you're not cheating. A photo with you, your wife and another woman all naked would be an awesome way of showing that you're not cheating, if your wife is down with it. You can also do the sign holding thing, make a sign clearly intended for other swingers to see, you both hold it and take a pic; helps if she shows some boobs, etc. Hope this helps!