My dog is being weird with a jacket?

So my husband is in Afghanistan, he's been gone for a while and I have a jacket of his I haven't washed yet. Theres a big pile of clothes on my floor, in it is that jacket. Our dog was sniffing around the clothes and stopped on that one, sniffed it for a while then drug it across the room and now he won't stop rubbing his face in it. What is doing? Is it because he smelled my husband on the jacket?