Quoting Mark Murphy
Hi, this is Aidan Moon, I am going through my friend Marks account because I am stuck in it. I have tried to log out, but it does not work. I also emailed Sean, but I have not gotten a reply. I would really appreciate if you could help me figure this out.

Quoting The Active One .

You might be stuck on his account on the internet. An example would be that my brother can't sign in. Do you have Mozilla Firefox? I think you might have to use Firefox from now on. Try using Firefox, it worked with my bro :D

--The Active One--

Quoting Mark Murphy
Hi, this is Aidan Moon, I am going through my friend Marks account because I am stuck in it. I have tried to log out, but it does not work. I also emailed Sean, but I have not gotten a reply. I would really appreciate if you could help me figure this out.

Quoting Chris Phipson
Try cleaning out the cache file. Sometimes there will be "left over stuff" in there that could possibly keep you logged in.

Try that and let us know if it worked.