It's not a route really, but just a scene. You can't skip it entirely, but if you don't accept her behaving a certain way (like if the MC prevents her from pissing out in the open), you'll shorten the scene a bit and hopefully (since we don't know the future) eliminate anything like that later on. So far, there's not been anything beyond that scene, at least not that I can remember.
I think she's mainly experimenting, seeing what the MC likes that she also does. If the MC doesn't really go along with her acting like a dog, she likely won't have a reason to try it again later.