After two years of hubby letting me keep my boyfriend/ex-fiance while he didn't play, I got over my jealousy and would approach acquaintances of mine from the gym, coffee shop, bookstore, from church even. We would date them together: take them to dinner, the theater, concerts, even on vacation with us (separate rooms), paying for everything and never expecting anything.
We would never come on to her, but create opportunities for her to take it further. Some, having been given the opportunity, were willing to fuck hubby; but only a few let me watch or get involved.
Regardless of the outcome, there were no hard feeling or regrets by anyone and we still occasionally get together with all of the women. Two in particular who are married have socialized with us from time-to-time with their husbands. Both guys know of their wive's past with us and have brought it up. With one we've had vanilla discussions about things like travel. The other husband has asked for explicit details. (I think he wanted to confirm the kinky things his wife told him.)
We have not, however, played with any of them again.