I have to children, and 21 month old and a newborn. My son, the oldest, is very jealous of the attention we've been giving our daughter, but my husband plays with him all the time. He wants to drink out of a bottle and be held like a baby. What can I do to show him he's the BIG brother now and not the baby?!
I have two children a 27 month old son and a 9 month old daughter. Although I would not allow him to regress and drink from a bottle letting him be your baby will not hurt him in the long run and the more you push him in to being the BIG brother the more he is going to resent the new baby. And I know its hard being a new mom and a mom to a toddler He probably wants his mommy so I would set aside a special time just for the two of you when your husband or another family member can be there to help out with the new baby. If he wants to act like a baby play in to it a little if he wants to act like a baby treat him like a baby and say sorry babys can't eat cookies they will choke or what ever it may be this will 1 teach him somethings about babies so he wont try to feed the baby cookies and 2 he won't want to be a baby. And My son was great with my daughter from the day she was born ( he was also much smaller than you son only 18 months) But my friends and family have been in similar situations.
I only have an 8 month old son but I have heard that when siblings get jealous of a new baby, it's a good idea to get them involved in the care of the baby and give them a lot of praise and attention while they do so. This way, you can spend some time with both children, and make the older one feel like he is helping and gaining your attention. hope that helps!