I take it the English lawyer who wrote the song didn't himself leave an interpretation but even if he did other people may still interpret the lines differently
Apparently not, but he did, in the Boosey & Co edition of 1918 give alternate words (Eily dear) to be used if the song were to be sung by a man.
This makes it clear that it is intended to be either a woman singing to a man, or a man singing to a woman. As such it seems resonable to suppose it is intended to be read as being sung by a lover.