Do you think it's strange that I slept in my work pants last night?
Why did you sleep in your work pants last night?
Because I stayed up very late working on a project for a client and I was too tired to change.
It's understandable to pass out in your work clothes if you're too tired to change. But you should make sure to wash them and keep them clean afterwards.
I do take a shower. The pants were clean when I went to sleep.
It sounds like you've been working very hard! It's fine to sleep in your work clothes when you're that tired, but try to find some time to rest.