User blog comment:Emily Windsnap/Wait...does Arthur know who Gwaine is?/@comment-4769526-20120312205206

I've never really thought about that. Gwaine hasn't told anyone exept Merlin so far so it's unlikely that anyone else will find out. But you never know, maybe Gwaine's sister could appear for a episode or two and acidently let it slip that she and Gwaine are of noble birth.