Denu has awesome advice, she really does. I have met people from the internet tons of times. Some just friends, one more then that. When its meeting someone as friends, its so much better then meeting as potnental lovers. I havent ever had a bad expierence, i guess im just lucky. When i met the person i am with now, it was just friends at first, so it wasnt that hard, but there was some feelings, hidden. Its scary and your nervous, wanting to impress them and show them that you are as great offline as you are online. But what i found to be the best trick is to be yourself. You are more yourself online then you are offline i believe, you are able to share secrets, fantasies, storys that are rather embarressing becuase there is no face to face contact, so they cant see you blush or be mortified.
I'm getting a bit off topic here, just be yourself..they like you are so far, so what could he be dissapointed in? Your submission? If that is what you are worried about, im sure he knows this is your first time ever doing it in real life (my same situation), he, im sure would be more then okay with a few mistakes, and or slip ups when you are playing. Plus im sure he is more then happy to guide you. So no worries. We all had to be new once..

Good luck!