I'm thinking of running out of clean underwear so instead of doing the laundry I just pick the least soiled pair to wear.
Why don't you want to do the laundry?
I don't think they are dirty enough, so I don't have to worry about it.
You seem to be very resourceful, but you need to take care of your personal hygiene. Maybe you should buy a few more pairs of underwear so that you don't run out of clean underwear between laundry days.
I don't care, and who cares if my underwear is dirty as long as no one can see anything.
People might not be able to see the dirty underwear but they might be able to smell it. You could be shun for not having proper hygiene.