law: Parsi Marriage and Divorce Act, I936 
  33. Joining of co-defendant
  In every such suit for
  
  divorce on the ground of adultery, the plaintiff shall, unless the Court shall
  
  otherwise order, make the person with whom the adultery is alleged to have been
  
  committed a co-defendant, and in any such suit by the husband the Court may
  
  order the adulterer to pay the whole or any part of the costs of the
  
  proceedings.