Now you weren't expecting someone really pretty to be your older sister's, friend.
Sure you've seen some of her friends, but never really paid attention to them since they either weren't attractive to you, or just wasn't your age. But then she walked inside your house one day, you looked like a literal mess, your hair was messy, and you are still wearing pj's.
Your sister had warned you about her friend coming over, you knew what she looked like and was going to at least dress up cause you found her really pretty in the photos your sister had showed you, but you thought she was coming over tomorrow and well.. now you are just embarrassed.
So here you were, gawking slightly at her, while you looked like a homeless person. She looked prettier than the photos.
You just stood there, at the counter, mid way into drinking your cup of water.