Besides the relationship with him, make sure you are also creating a life for yourself. Do you go out? do you do things with girlfriends? When you do make sure look HOT (even if it's just to go to Starbucks and a bookstore!), and keeping a little mystery with what you're doing. I would tell my husband I wasn't going to get involved in any serious relationships until the divorce was final, but I did say I knew a lot of nice guys ("just friends") and might date some after the divorce. That seemed to put him on the edge...
The trick with this is you don't want to make them so jealous so that they run to OW, but you want to make them consider that they could lose you and that.... heck, you are one popular chick!!!!