For those in relationships, how many of you have a JO bud behind your partbers back? If not how did you bring it up to them?

Just wondering how many of you are doing this without your wives/GFs knowing? No shame here, just curious. For those that are out in the open about it, how did you bring it up to your partner?

I was in a 10 year relationship with a woman with whom non-manogamy was never a taboo subject and had a few experiences during that time. We we broke up a while back and now im dating someone new, sill have desires to have a bud and unsure of how to bring it up. My current GF is bi too and expressed some interest in non manogamy before we were "official" but hasnt brought it up since. I dont want to blow up my relationship by bringing it up but i also dont want to sneak around behid her back. Just curious how you buds have breeched this topic with the woman in your lives and how they reacted.