When the family gets together, everyone helps out to make it a success. Cousin did not do projects with his uncles or cook with his aunts, therefore, he chose to clean. If he thinks washing dishes is beneath him, then he should have taken the initiative of doing other work, instead of trying to get away with doing nothing. That does not speak well of his work ethics or of his ability to support his family in the future*.
As a grown man, he should be able to see this and have taken the proper actions, instead of having his father intervene in his stead.
Ok, tempting but I would tone it down if I were to really send this message.
*if they have traditional gender roles in mind, I have no problems with using it against them