no.

I used to have a lot more trouble saying this word. I felt that it needed some excuse tagged onto it like, "no, my hamster died," or "no, I have to shower and change," or "no, there is a tornado warning tonight and I have to stay in my basement." In your life you must remember that "NO" is a complete sentence. Why did it take me sixty years to figure this out?

Could I feed your cat today? No.