If these are hometown friends, he can meet them individually or in small groups that don't include the OW. He can have lunch with a male friend, or a drink after work. He doesn't need to hang at a bar with the friends that include her. That's over or you two are over. He can't be trusted doing that. He's proved how untrustworthy he is in social situations with OW.
He can be there for their graduations, weddings, christenings, parents' funerals and send a birthday card. He can do this without hanging with the crowd and OW for a day. Show up, be supportive, call on the phone later and leave. He isn't required to sit in their homes with OW there to be a friend. He can be a friend one on one with each.
If he picnics at the stadium at the ballgame with the crowd. That's over. He's proved he can't be trusted in those situations, so the two of you can show up with tickets at game time, near some friends and far, far away from OW so you cannot see, hear her or meet her eye. Better yet, he can do penance by skipping a season with these friends until OW finds a new job and moves to the end of the earth, or until you do. Or giving up games and watching them on TV.
He cannot go out to the bar and hang with the crowd that includes her. That's over. He's proved he cannot be trusted in that situation, so he can shut the h*ll up about his whining and find another bar, other friends, for music and watching games.
[This message edited by Heavy Sigh at 3:40 PM, July 19th (Friday)]