I get into trouble for wearing my slippers too
Just two days ago, I had to bring my son home early because he wasn't well and I had to haggle with school guard because I wasn't dressed proper...
I told her I have even worn them to a wedding and she kept pointing at the notice with pictures of how to dress with a big red cross on slippers hahaha
She eventually let me in and now I have to make sure I have non-slippers in my car for these situations ;p