Honestly if your first offense was not grief then why would your "friend" call grief on you, and has now done it for a second time? Also, what kind of friend does that?? You haven't made a strong argument at all towards your case for this time or the last, and I think two days is more than fair. If you need proof I do have it, but you're not really denying anything so for now, I'll leave it at this. Hopefully when you get back on tomorrow evening you will have learned your lesson and stop griefing - regardless of who it is. I also suggest changing your passwords and no longer sharing your account unless you want to pay for what they do when you're not around to supervise.