Welcome back! Your posts always remind me to cherish every moment because kids grow up way too fast. At the moment, I'm slowly typing with 1 hand and have S3 sleeping in my other arm - it won't be long before he's too big and grown up to snuggle up with!
Regarding your H, I think if you are going to have any expectations at all, they should be that your H will continue to do this connect/retreat dance with you. It seems to be a pattern, not only with your H, but other returning S's as well. I know it feels like a long time, but looking at the big picture, 18 months isn't all that long.
