Okay..Obviously it was not the best decision that Buffy has made..She went with her heart not her brain. It was dangerous to hide Angel...But her emotions got in the way of her thinking clearly, which tends to happen A LOT. I sympathize with her when she did this...She was afraid of what her friends would think if she told them, though it does not entirely excuse her for putting everyone in danger. She was wrong, but it easy to forgive her..considering the hell she went through in the previous season.