Hm that's crazy. Why will someone even marry his cousin in the first place. That sounds weird. Well, I can't say it has never happened in my country because I don't know every history but trust me, it is very much prohibited here. It is not done.
Anyway, different countries with different tribes. Also, people are taking offense in any little thing that another person says and that is why it is quite difficult to advise someone now. We never can tell what they will do after taking the offense
It is very strange if it happens anywhere at all. I don't know why they don't change the law here - I don't think it is common now.