I would try to shift to not offering lies but maybe responding with half truths if he asked. When he was going away, I wouldn't say anything; if he's insecure/wants to be needed that's his responsibility and he has to ask if he needs to know, "Will you miss me?" before you comment. I would tend to answer something along the lines, "I enjoy being with you, you know that! Why else would I be married to you?" It seems to respond to what I perceive as his need in asking but doesn't directly answer the immediate question of will I miss him in this instance.