What Would You Do In This Situation?

Although this invite is pretty much the best thing to happen to me on Facebook yet, I'm not quite sure how to respond.

Love ya Greg!

Background: HoboWars is an online role playing game in which you play the role of a hobo. You fight against other hobos and pick up cool hobo stuff like shopping carts. My brother and a bunch of his friends are like majorly into this game. The other interesting thing about this game is that it the actual gameplay is really primitive, like it leaves a lot to the imagination. There aren't really a lot of graphics, it seems to be mostly text. Also, I heard that this game originated in Australia. The perplexing reasons for this game's popularity are why I find it to be so interesting, although I have never played it. Greg is so into HoboWars that it is rumored that he must tend to his hobo before he kisses his wife goodnight, and that sometimes he wakes up in the middle of the night just to move his hobo. Sounds like internet crack to me. And now to make matters worse, it's somehow it's been mashed up into a Facebook application. I guess this is why all these nerd writers are predicting that Facebook is going to take over the internet.