The point is that Tsubaki and Urabe (and Oka to an extent) can literally share their feelings with each other, which allows them to understand each other in a way no other people can. And when Tsubaki and Urabe go all the way (which I hope is before Ueno and Oka do it 'cause I'd like to see Tsubaki one-up Ueno at least once in this series
), I think that they will open up their hearts and minds to each other and become one in a new and different way.