According to the CEO of Levi’s you should never wash your jeans. He stated he has not washed his jeans in more than 10 years. Word is, that you should spot clean your jeans with a brush or damp cloth.
I’ve also heard of putting your jeans in the freezer overnight to eliminate odors or to keep germs. Not washing jeans allows the life of the fabric to last longer. Kind of unique, I know! I’ve never personally tried that, but it’s something I’ve heard.
I usually wear a pair of jeans a few times before I put them in the dirty laundry to be washed. Obviously, if they are dirty they are in the laundry a lot sooner.