Hi, I know you weren't asking for advice, but I just want to say that I don't think you need to get too hung up on THE BIG MOMENT WHEN YOU TELL ERIC YOU LOVE HIM. It doesn't have to be some huge, overwhelming thing. The fact of the matter is you simply love both him and her. So, you can say it simply without apprehension, just like you would tell a friend you love them. I know it seems so much bigger than that, but love is love, and if you don't lay it at his feet as if it's some earth-shattering revelation that he must have some dramatic response to, and just express it when it feels natural to do so, I'm sure it will be well-received. For example, you might find yourself feeling tender toward both of them at some particular moment and be spontaneously moved to say, "I love you both." And then let it be, without expectation of what he will say back or any need to explain yourself. It's not about the words, anyway.
But I am really happy for you. Sound like the relationships are in good shape.