the vet tech said "kennel cough"
the vet said reverse sneeze.
this video is EXACTLY the noise and what Lily does. https://www.dogingtonpost.com/reverse-sneezing-in-dogs/
scroll down once on that page to the Mr Puggle reverse sneeze.
we visited the vet again and he prescribed a low dose of Prednisone over the next 10 day.
fingers crossed.