What should i do?

My husband seem to think our 4 year old daughter is invisible. She ask him repeatedly all day to play with her and he just keep sending her to her room. The only time he does play with her, is if his son from a previous relationship is visiting, (which he is 5 years old) and he would play with them both with our daughter toys. But once His son leaves he's back treating her like she doesn't exist. I explain how it makes me feel and how he hurts her feelings but he think I'm "hating" on his son and their relationship. Idk what to do.... Thanks for listening!