So about 20-30 minutes after I posted my "I think I've done something bad" rant, my boyfriends brother came home.
Apparently, he had come home while we were out in town, and had left to go visit a Games Club in another town.
So, put bluntly, the little turd ran off to say Dungeons and Dragons without telling my boyfriend where he was going.
So luckily it wasn't anyone's fault but his.
That's a massive load off my mind.