if there's siblings and parents, why aren't there uncles and cousins?

if there's siblings and parents, why aren't there uncles and cousins?

I'm sometimes having layouts like this:

<div>
      <div>
            <div>I click here</div>
      </div>
      <div>
            and something happens here, e.g. slideToggle
      </div>
</div>

I have to write   $(this).parent().siblings().slideToggle("fast");

I'd love to write:   $(this).uncles().slideToggle("fast");
To be correct in a gender way there maybe should be an aunt as well.

For the following cousins would be great:

<div>
      <div>
            <div>I click here</div>
      </div>
      <div>
            <div>and something happens here, e.g. slideToggle</div>
      </div>
</div>

I do understand that maybe there are not only positive aspects of this suggestion, how do I implement this as a jquery plugin?

cheers, venkman ( a webdesigner who loves to write less as humanized as possilbe ;)  )