How do you make sure your girlfriend/wife leaves on her good clothes/make up on for ?

Whenever we go out to a fancy dinner and come back home she says "Give me some time to get comfortable." before She then takes off her good clothes make up and comes out with sweatpants and and the same robe she always wears, and hair roller things. it kills the mood for me and she doesn't looks not as attractive as before when she was dressed up. How do I make sure she keeps on the good clothes for without makng her feel ugly?