That is to say, a fork is flying through the air, from where Sebastian is standing and straight out the window. It misses Gwaine's head with a good, safe margin of several inches, but if it had hit it likely would have hurt quite a bit, considering the force with which it flew.
Or, you know, was thrown.]
My, my. Dinner guests are typically expected to enter through the door. [At least Sebastian's tone and expression are nothing but amiable – amused, even - as he turns around to face the would-be chicken-stealer?]