S.M.
Hi - I am a SAHM with two kids, and another one on the way. A 9 month old is going through some phases, and your son's reactions is totally normal. Keep trying to get him comfortable. I picked one person for my first child to bond with, and invited that person over for time with our family, and then time one on one with my daughter. This way when her special person came over, my daughter didn't automatically think we were leaving and freak. It will take some time, but keep it up. Before you know it, your son won't even stop to notice that you have gone . . .