When Sam was able to choose, he would be drawn to dolls, fluffy things and stereotypical girls’ stuff.He has an older brother, so where did he get the girlie toys? Answer - Mama.
Who bought all those frilly little outfits? Answer - Mama. Who has messed up this boy's life? Answer - Mama.
Precisely. Mama felt cheated when she gave birth to a second boy, so now she's turning him into the girl she wanted. Sick.