Today's Seeker has wisely turned to the Sage, albeit indirectly, for the Sage's great dispensation of wisdom. (The Sage's Minions have repaired this link.)
The Sage recognizes that this is a very important woman in your life. After all, what more can a man ask for than a woman who does NOT lie, cheat, or generally treat you like human excrement? One surely can ask nothing more out of a relationship than to remain unabused. Lesser Advisors would recommend that you either cut your losses or insist that she get therapy for the problems which affect her shows of intimacy.
The Sage discerns that you that you must insure that you never lose this special relationship. Only being "with her", and not being legally committed to her enables her to leave at any time. You must insist upon a wedding, as quickly as the laws in your state permit. We all know that when someone gets married, all of those annoying or quirky habits only get better, once the need to impress each other has become less imperative. Since you don't want to annoy her nor to hear her complain, you must also purchase a second bedroom suite for yourself, to put into another bedroom. This may require you moving into a larger home, but no sacrifice is too great to bear for such a close, satisfying relationship.