An Entryway Perfume Sprayer in Development That Reacts to a 'BAD' Smell Reading
Auto Perfume Sprayer | ProtoPedia
Auto Perfume Sprayer is a work-in-progress device intended to check a person's odor as they return home. A smell sensor feeds readings to a microcontroller; when the result is classified as 'BAD,' a servo presses a perfume bottle to spray automatically.
Makers BULAT IARKIEV and Yadanar Htay describe the project on ProtoPedia as a way to respond to odors that people may not notice themselves, such as after exercise. The project is currently marked as in development.

Come home and the doorway silently judges your smell, then responds with perfume. That's a rather opinionated welcome.