Hey everyone, I'm having a slight problem with the skin binding and you'll all probably think I'm dumb, but I am so dont feel bad about thinking it

When I bind the skin to the Iiko and try to move his arms, the ear and the chest under the arm follow. When I move the arm down, the ear stretches after it, when up, the underside of the arm extends outward like a shoulder blade on steroids. Can anyone help? Thanks.