You're the best person I have in my life.
I know I'm nowhere near the easiest person to deal with... I'm actually kind of an ass most of the time - but you've always been there for me when I needed it (and even when I didn't want to :P)
We've been through pretty shitty situations, these last few years for example haven't been easy, and if you hadn't been there I'd have given up long ago.
This is a very important summer for me, and I'm glad you're here to listen to me blabbering about my non-existent problems or be amazed by the stupidest shit. But, I'm mostly just glad that you're here.
It's an important summer for you too, and I wish you the best, and I hope you know that I'm here for you too.
Happy birthday, Diane. :)