limit and sort options don't work inside chained call to relationship API

If I call the API as follows:

$result = civicrm_api3('Contact', 'get', array(
'sequential' => 1,
'return' => "sort_name",
'id' => 109,
'api.Relationship.get' => array('options' => array('limit' => 1)),
));

I would expect that it would return at most 1 relationship, but it returns all relationships instead.

The 'sort' option is ignored as well.