Well, the way you did it that time is the natural way. Your couple didnt advertise for a unicorn, you just dated the guy and it turned out you liked the wife as well! It couldve gone bad if they werent experienced and he wasn't cool with you actually loving his wife "more."
I mean, I've got a bf now and he just so happens to get along well with my gf. They have a nice friendship. Friends with very occasional benefits. But miss pixi and I didnt advertise for a "man to complete our relationship," or to "add" or to "share 'our' love with" or anything like that. I got a bf, he and she got along, bada boom bada bing. And Ive been dating since I met my gf over 4 years ago. It took me 3 years to find a bf who became Mr Right, and also a good friend to miss pixi. 3 years!
Love withers under constraint; its very essence is liberty. It is compatible neither with envy, jealousy or fear. It is there most pure, perfect and unlimited when its votaries live in confidence, equality and unreserve. -- Shelley
me: Mags, 59, living with:
miss pixi, 37