Jealous

My son has become so selfish recently. He doesn't like to share anything with his sister. He'll grab everything from sister's hands.

He is trying hard to grab our attention by making silly stunts, spinning for few rounds, etc.

Whenever we carry his sister, he'll scream and cry until we put down his sister. If not, he would like to sit side-by-side with his sister.

When he is NOT eating, we'll tease him and pretend to feed his sister. He'll quickly swallow the food eventhough he doesn't like it.

When we put his sister on a mattress, he'll quickly lie besides her and disturb her.

I'm afraid the fight will be erupted soon.