If I'm guessing, the chaplain position is an in-house staff position. Is he ordained though another group?
I would imagine that during the ordination process, the Bishop would inquire about his marital status. The Episcopal Church is not known for it's sound biblical theology, but I imagine they would prevent him from being ordained if they knew he was having an affair.
I was once on the track to ordination and I stopped the process because of my wife's affair. The people in charge felt that though I was not "at fault", it was not wise for me to pursue the ministry with a marriage in crisis. They were right.
I would pay good money just to sit your husband down right now and have a long conversation with him.
