G.V.
My opinion: Your son is jealous of his little sister and that is perfectly normal for him to feel this way! And instead of saying that to you - because he is too little to realize this himself - he is showing signs of not wanting to leave you. He is jealous that little sis gets to stay with you and he has to get shipped off to school or daycare or the library. Suggestion: Can you find someone to watch your 18 mo old while you take your son to school or the library? If you can't, then take your son to the Library or wherever on the weekends and have your husband watch the 18 month old. Or maybe for the first day of school, your husband can go into work late and hold the baby and YOU can be the main one getting your son off to Kindergarten. Your son is just stressed out because the baby gets to stay home wiht you, that's all there is to it. He feels that he is missing out and you are having great fun with the baby and he's not number one with you anymore. Hope my advice helps if you decide to take it. Good luck.