@linaetra for ME personally, it's about aerith. but since he doesn't mention tifa or aerith like red and yuffie do, i just have to leave it up to interpretation.
@linaetra barret can be toward either one of them.. it's very ambiguous because he asks 'who is it?', your soulmate, whoever it is, you gotta tell them, don't wait until it's too late. it could foretell the loss of aerith, or it could be losing tifa because he's aloof. that's just my take.