Why did you have to make a big deal of it? You did, as soon as you went to check it. Once you did that, the situation was toast. You knew it was an arguement with history, and you pushed it. And then you had to be right. I think you should think about this and generalize it. I think I can give this advise, I have been known to have the same problem! I doubt if the difference makes much difference to guinea pig!
