Big Brother Adusting to Baby Sister

I have a 2 year old boy (3 in October) and a 9 month old girl. My son has never came around to our daughter. He will sometimes be sweet to her, but most of the time he wants nothing to do with her. He doesn't want her to play with him or his toys at all. We eventually thought he'd finally start playing with and loving her, but it hasn't gotten better. Has anyone else had this issue and have any advice? My son is extremely jealous and if my daughter comes over to me my son runs quick to me also and says "no, my mama". Earlier today he didn't want her playing with his toy and when she crawled away and he said "yay, she went away!" Is it just his age and him being a boy or is there a certain. Way to handle it? It hurts my mama heart that she loves him so much and he could care less. 💔 😏