M.B.
Have you or your husband tried giving your older son more attention when the baby isn't around? I have two sons that are 2 1/2 years apart and the biggest issue ended up being that we spent too much time focusing on the baby and not enough giving him the attention that he needed. At this age, the intellect and interests of your sons is really too diverse to expect your older son to want to play with him. It will be a few years before you can expect that your son would enjoy activities with his brother. Also, your son is really too young for him to intellectually understand why he is doing what he is doing. He likely is doing it because he DOES get attention from you when he's bad. What you might consider doing is doing activities with your older son that he would enjoy and bring the baby along - movies, parks, etc. At this age, the baby likely will be quite content to just be with his mother and brother.