Just ask yourself "how would you meet men if you were single?" It's not that different as long as your husband is on board. I tell friends of ours, that know about our lifestyle, that my wife simply dates other men. She will get to know them before taking it into the bedroom like any single woman would.
My wife does not hide what she is looking for. In her profile, it indicates that she is married. In her description, she says that she is a happily married woman seeking a lover with her husband's approval. When she meets a guy, or starts communicating with him, she will explain further. She will tell them that not only do I approve, but I may want to watch and possibly join in for a threesome.
If the guy is against any of this, it's probably a no-go. However, over the years, we have rarely had a guy that disapproved of my presence or participation. Most guys are exhibitionists and love to be watched, lol. And, most guys love fucking another guy's wife right in front of him, lol.