In a sense, each relationship is unique and special. Like when I was in a triad, we would have separate dates because each pair of us had different interests. We would respond to each other differently. So in a sense, I felt the relationship itself was unique enough, which led to different behaviors and mannerisms.
Where it got odd was when one person learned from another and brought it into a relationship. Like I remember once saying, "You never kissed like that before." I knew she must have got that from her girlfriend. But I saw it adding to the relationship because she found out something new she liked.