Some people just have a very jealous nature. He is excited about the possibilities, but still nervous because of the possible outcomes. First reassure him that you guys are in this together, never ever seperate. Second, have him set up any meetings with others that you may have. Just tell him if he sets it up you would be willing to go along, but it would be up to him and for his pleasure. Next when and if it happens, make sure he is included from start to finish. Afterwards, pay close attention to him and be careful how much you say positive or different from you two together. Especially include anything negative and everything that your husband does better. I know you shouldn't have to do all of that, but when he recognizes how much you love him, he will change his tune. It is just a little insecurity mixed in with the jealousy. Soon enough he will totally back off and not feel threatened at all. If he is like me, he will feel best when he sees and knows you are satisfied.