Biddy does the same thing! It's so sad, I hate to look at her in the window when we're leaving
The good news is that I don't think she sits there the entire time that we are out. If my boyfriend leaves and I am home alone with her she'll sit in the window until he drives away. Then when he comes home she runs like a bat out of hell back to the window! I don't know how she knows that it's him! We live on a pretty busy street & there are lots of cars that drive by all day long! It's amazing!!