Dog plays with me not girlfriend

My girlfriend has an american eskimo, about 7 years old that was a rescue dog from a pound about 4 months ago. He will occasionally growl at her if she is giving to much what I call human love, kisses on the nose, hugs around his neck or when she picks him up to hold/hug him. He will dog play with me batting me with his paws, playful mouth, roll over etc. But he will not do it with her, any ideas why?

Thanks!