The feeling of being connected at the soul on a mutual subconscious level where great co-dependency exists. To love someone in a familial mannerism while without the actual blood connection while retaining a feeling that this love should be a sacred form of love that is ineffable. While sexual attraction is felt, the feeling would survive on a Platonic basis. Unlike love or lust, lovelyn is considered much more sacred, and indulges the emotional and physical flaws along with the emotional and physical attributes as being beneficial to strengthening the tie and co-dependency of both parties involved. Lovelyn is also different from love because it requires that both parties feel the emotion in order for it to exist. Without the mutual co-dependency lovelyn cannot exist. A state of lovelyn must be entered subconsciously and cannot be changed by logic or reason. Religious terminology would allow us to explain this connection as a mutual connection of the soul. Psychologically lovelyn can be very destructive to one or both of the mental parties engaged into it if one is lost from the other.
I know Jay and Eve are in a state of complete lovelyn because they simply cannot live without one another.