It's a very old internet joke. You said your girlfriend is gone for a while, and the joke is that you don't really have a girlfriend...that "she" is really your own hand (if you get what I mean).
Therefore, bronto asks if you hurt your hand, and they is why you say your "girlfriend" is gone.
And, as with most jokes, explaining it makes it less funny.
![Smile :)](https://forum.c-rpg.net/Smileys/default/icon_smile.gif)
But now you know.