Your spouse doesn’t have to want to do it. But they are doing it. Be grateful. And express it in the full. Don’t insist that they should ‘want’ to do it for you.

Express your gratitude fully; include how whatever they just did enriched your life (or made it easier or better).
“I know you really didn’t want to take the kids out do I could nap, but you did it anyway. Thank you. Now, I feel much more energetic. And I know you care about me. Thank you.”
– Hey, they just may do it again.

This is much better than “You should want to do this for me. You know how exhausted I am …”