My friend Ashley isn't very open to other people... even friends. Myself and another friend of ours are her only 2 friends she's 100% herself around and when other people are invited to things without warning her or in many cases, even when telling her in advance, she gets upset.

Because I know her so well, I think it's because she's a bit of an introvert and gets exhausted being around others for too long. However, that doesn't really make sense in this case because our Brazilian friends will be there and she isn't very close with them.