Advice what do you do when one grandparent favors the others over yours? And I don't wanna hear it's…

Advice what do you do when one grandparent favors the others over yours? And I don't wanna hear it's normal cause it's not in my book. His 15 months right now and they just act like they don't care about him compared to the other two. I just don't want him to grow up feeling unwanted or something wrong with him.