Dear Massi,  I was at a wedding with my wife. My cousin was sat next to us. 

When me and my wife got up to leave, my wife sent me back to the table as she forgot her dupatta.

When I got back to the table I found my cousin kneeling down like he had lost something and was looking for it. But he was holding my wife's dupatta and was smelling it. 

I snatched the dupatta off him and tried to act like nothing had happened. 

Now there's another wedding function coming up and I know if I see him again, I'll probably end up punching him.

My wife says I'm making a big deal out of it. Do you agree?

Massi says, You have turned something potentially innocuous into a personal vendetta. 
Your cousin's actions were effectively harmless.

The smell of perfume or any other aroma may have have evoked a nostalgic memory for your cousin which may explain him smelling the item of clothing. 

If you have never had reason to question your cousin's actions before, don't allow this incident to strain your relationship or aggravate your temper.