Why doesnt Vin ever talk about his brother?

Vin is all about himself that is why.

A person who wants to be center of attention and if mentioning his brother would do that he would bring it up but it doesn't.

The same reason Dennis Quaid doesn't talk about cousin Eddie

I think that would just raise too many questions about their paternal parentage and the circumstances of their conception, since Vin is black and his fraternal twin, Shane, is white.

I don't think anyone got it. Shane is awesome in his own right. I love his work.