My son (5yo) doesn't like our cockatiel.

We got Bilbo a month ago. He immediately liked us and felt comfortable with us from day one. I'm deeply in love! My son, though, doesn't seem to know how (or want) to interact with him in good ways. He'll threaten to poke the bird through the cage, chase him around, laugh if he falls and absolutely not listen when we tell him to stop. It feels like he's a jealous older brother. Today he said he wants to return Bilbo. I thought this was common behavior but yesterday a friend of my son came over and was so sweet about the bird. He wanted to pet him, be around him quietly, asked lots of questions and I couldn't help but compare them and feel sad about it. The weird thing is that my son is usually the quiet thoughtful cute one and his friend is usually the hurricane kind of kid. My son used to act the same around a cockatiel that a friend of mine had, but that one was wat less sociable than ours and I thought it would be different when we got to bond with a bird in our family. I'm not getting rid of Bilbo. Need advice on helping my son bond with the bird. Thanks!