Dear Unloved One,
I am sorry that you have come to such an impasse in your relationship. It is not uncommon, but it is unsatisfactory. You did not tell me how long you have been together but statistics show that the average relationship lasts 3.9 years, about the same amount of time that dopamine influences the passion circulating in our love affairs. After that one needs to be sufficiently grounded in a true partnership or develop other satisfying elements in the relationship to offset the loss of the novelty of the dopamine driven hormones.
I would also ask myself how are you, in any way contributing to the loss of romance in this relationship? Some women turn off their feelings for other people when they fail to reciprocate mutual responses. Act on your romantic feelings with overtures that are both inviting and personal. Talk to her about your feelings and needs. Threats never work to provoke romance. Being vulnerable however does sometimes work.
If, after communicating in a very real way about the direction of your relationship you continue to feel like a non-entity in your twosome, you may wish to move on and find a love that is better suited for your emotional and physical needs. But do not forget your spiritual needs as true love comes from the soul and is only quenched when both souls are conscious, alive, and inspired by each other. So bring flowers, quote me, and try to make real contact and if that does not work, you will have your answer.
Best of love luck!