I think maybe its about a relationship that has been kind of stopped because the 2 people have not been able to see each other (one moved away or something) and that he still very much wishes things could go back to the way they were and the other one may feel the same way but is denying it, maybe even denying that they ever even loved him so he is reminding the person how they "couldn't hide it" and "everyone knew it" ( that they loved each other) and "I was the sea and sky, was you" meaning they meant everything to each other but then something happened "a big black cloud came rolling in" not to stop them loving each other, but to stop them seeing each other?!
"I wonder who you've seen, and i hope that he's a friend" - he hopes that he hasn't been replaced
I think maybe its about a relationship that has been kind of stopped because the 2 people have not been able to see each other (one moved away or something) and that he still very much wishes things could go back to the way they were and the other one may feel the same way but is denying it, maybe even denying that they ever even loved him so he is reminding the person how they "couldn't hide it" and "everyone knew it" ( that they loved each other) and "I was the sea and sky, was you" meaning they meant everything to each other but then something happened "a big black cloud came rolling in" not to stop them loving each other, but to stop them seeing each other?! "I wonder who you've seen, and i hope that he's a friend" - he hopes that he hasn't been replaced