Couples are fun, especially when the woman is "really" bi-sexual as myself. I am Zana XXX star. I actually have done films with women and enjoyed every single one!! (done almost 250 total)... If you want to meet that would be fun!
Love
Zana

My experience with this

The attractive single female that wants to join a couple for sex is very difficult to find. It would seem that it is easier to find a Unicorn. You can run ads, try AFF etc. Most that I know never found one that way.

Next option is P2P. You need to make sure your lady is accepting and supportive of a paid companion. In my case I didn't bring that up because it would have been end of both the conversation and the concept. The blonde would have said, "I can get a pair of Jimmy Choos for that." The advantage of P2P is you can set it and schedule it. It also lacks the spontaneity of a classic, "why not" moment, that adds to the experience

The way we got involved was through lifestyle clubs and resorts. The blonde needs the social interaction first to become comfortable with anyone we would want to play with. She has become really good friends with two of the ladies that she has slept with. We see them several times a year. They are the gift that keeps giving as I get my turn as well.  

Most everyone we know, used the lifestyle to find a bisexual/bi curious females. To be fair those are the only people we know that have had experiences.  

Disadvantages are that you need to travel to find the best of these places. Desire in Mexico is a good example. There are a couple around Tampa, I can't think of the name. It's one thing if she is looking for another girl. If you want to be involved, the odds are the ladies guy will want to bang your wife. Some guys can't handle that.

Good luck.