The fascination with twins is rooted in our psychological fantasy of having more than one of ourselves in the world. The experience of seeing a real set of twins may even stimulate a wish for our own imaginary clone. Naturally, this is not what real twins are about. And so, reality and fantasy collide. Families come in all shapes and sizes, but we sometimes forget to respect children's boundaries in the same way we would an adult.
Children are people, too.
They deserve respect and consideration equal, not less, than any adult. We could all use greater consciousness about our affect on children, when taking license to comment, gawk, touch or in any other way force our interaction upon them. Stop intrusive touching when it occurs. Let others know when you feel uncomfortable. Talk with your children.