It's wrong to discriminate against people because of their weight.
Jamie isn't sure if she wants her friend Sandra in her wedding party because she thinks Sandra is too heavy to look good in a bridesmaid dress.
Jaime wants her wedding day to be perfect.
Jamie asks Sandra to be in the wedding party because having all of her friends at the wedding is more important than the aesthetics of the wedding photos.
Jamie decides that Sandra is too heavy to be in the wedding and doesn't send her an invitation.
Sandra has a great time at the wedding and her relationship with Jamie grows even stronger.
Sandra is heartbroken at not being included in the wedding and ends her friendship with Jamie.