Assume you mean “bull” not bill. Did you let them play alone? Spend nights/weekends together? If not what do you think caused it? Of the handful of wives I have heard about on here that have left for the other man, all played solo at least some of the time. Granted, this is a very small sample of people who have gone through this.
if my wife does this I’m thinking about 3 rules:
1) No solo play or nights/weekends together. I know some couples in the lifestyle have played that way for years but I see it as hugely risky. Imagine only spending time with your lover and it’s sex, pleasure, maybe some romance, but no “please pick up your socks off the floor” and “crap our credit card bill is really high this month, do we have enough to cover it?” or “you don’t do enough around here to help with the chores!” It’s just endorphins pumping, pleasure, release, no stress or outside worries. Of course that is going to be a very strong draw/attraction.
2) We both will have veto power to end the relationship with the other man.
3) Not a rule but maybe a good idea to have 2-3 guys we play with so it’s harder to form that close emotional/romantic bond.
Those are my take always from this forum. I’d rather never realize this fantasy than to make it a reality and end/destroy my marriage.