Responses
I have this headcanon that she was a fujoshi drinking in a bar.
On another note, I think it's because the lady shows that they as a gay couple are getting accepted by people. It shows a over all change since the uke was always so worried and thought that he was disgusting because he was gay and the lady seemee happy for them. So that scene represented a bit change in the story.
the weirdest thing is, i was so happy when the drunk lady near the end seemed happy, when yuusuke smiled as saya came in