Cure his jealousy
The answer to your problem is more affection, constant affection. My wife has 3 lovers and I don't have any. I don't really want any at this point, because in the past it has caused her great anxiety. I used to be jealous too but now I revel in her happiness, and the 3 other men are a safeguard, I suppose, about any one becoming all-consuming. The way we combat any occasional jealousy on my part is that she gives me constant reassurance that I am the love of her life. Her polyness has only deepened our relationship. We have incredible sex and she always put me first (for one thing, we agree on the time of her dates and she always asks me first if they are OK). She hopes to get to where I am with a lack of jealousy but I am in no great rush for her to. I'd rather play golf-- I even play with one of her boyfriends -- than rush into another relationship. Different strokes I guess.