Methinx that if you go forward in your fantasy you ought first to determine a fail point for its demise, or a safe point for a possible return attempt, in case of cold feet.
And remember to have a 'safe' word.
Really important is who chooses the 3rd member. If you're adding a male you and her must be in it together. I suggest he (3rd) needs be willing to touch a male and be touched by another male. That doesn't mean it WILL occur, nor that you are willing (you might be unwilling, but, he doesn't have to know it). It's a safety net, for you to be in the bed and at the ready for the emotional security of your wife - yours too.
Another point to ponder is the familiarity of Mr.3rd. I recommend a friend not so close to you but familiar to you both and horny enough to diddle your bride and know that it's a single instance. A one way ticket. Health of skin with no herpes and other shit is kind of big.
Being loaded and the guards lowered is one thing in being so willing to experiment.
Being fully prepared and eyes wide open going in with the knowledge that your heart will develop a new facet for your aspects in love is entirely unchartable territory. You need to be aware that you may end up with a white elephant in your living space. Getting rid of it could prove problematic. For each time you try to move it a bear pops out and takes a bite out of your ass, or marriage!
Be tight, strong as tightest friends first.
So, it's like the song says, "Will you still love me tomorrow?"
If you're going to add in a female, then let your wife do the choosing. You need only be there in the bedroom watching, enjoying and pleasuring your wife and/or the mistress upon request.
I could be that Mr.3rd.
