I'm intrigued by the idea of "oneness". But ultimately, truly, I see it as an unobtainable ideal when applied to a a "coupledom" or "three-or-more"-some. This, to me, is an "all or none" phenomenon.
First, I learn to be "me" in a wholeness in-and-of myself. At the point that I can include others in in my wholeness...I can't fathom a way to exclude anyone from it. This may be a result of my inquiries into "secular buddhism" but...if I am willing to let another into my "all" then I am willing to let "all" into my "all".
My relationship to each of the "others" in my "all" may vary in degree and level of interaction. But, at that point, that I am can envision letting others enter as "myself" - then I have a "relationship" with each (and every) other "other" that exists. Because we are all people, because we all relate to one another on some level, because to understand myself I have to encompass all of the other potential "me"'s that exist (i.e. the people I would have been if I had been born into another family, experienced other experiences, etc.)
Some of these "others" are close to me - I have met them, I am their friend, I am their lover, I am their partner...the majority of these "others" I have never met...but we are bound by bonds of humanity/life/existence.
For me, I am myself, whole and complete...or I am a part of everything, whole and complete...there are just pieces of "everything" that I am more, or less, familiar with.