Why is my toddler mean to her dad?

Our daughter just turned 3 and we are expecting a new baby in a few months. My husband is extremely involved and I can genuinely say that he is an amazing dad. For the last few months, our daughter has started being mean to him. He walks in the door from work and she immediately changes her attitude. She pushes him away when he tried to hug her. Kicks him when he tries to play with her. She pushes him away when we try to read a book together at night. She yells that she doesn’t want him...the list goes on. She’s honestly a very good kid and this has caught us both off guard. If anyone has any advice on how to approach this, I’d really appreciate it. It’s to the point where my husband is crying about it and I don’t blame him. TIA.