Well, I don't know all the rules either. I can tell you where the photo came from, but I don't think I could figure out how to create a link.
But if you are ever tired of this board, here is a wonderful site to check out: www.pixdaus.com
If you search on Love Birds, you will see the picture I used.
I found the site when someone sent me an e-mail with a whole bunch of pictures, and one of them had a sort of water mark of the site name. I haven't had the time to find the photo I was looking for (I wanted to maybe find the photographer and buy a print). I'm still stuck on the category "Bridge" which has some of the most awesome photos I've ever seen. Hundreds and hundreds of photos, just of bridges! Photos are submitted by people all over the world. There are also vintage photos. Search on any subject and see what you find!