All Seated on the Ground, by Connie Willis
I love Connie Willis. She can be too long, but even then I don't mind too much. And one thing about Connie Willis is that she frequently indulges in screwball SF comedy, usually with a romance attached. She is the only author I know of that does this, and All Seated on the Ground is a good example of it. It's also a Christmas novella!
The aliens have landed! Finally, they really have; aliens landed in Colorado, but all they do is stand there and glower disapprovingly at everyone and everything. They don't speak, they don't respond, nothing. Meg is on the welcome committee, which has been trying to communicate with the aliens for two months now, and all they've managed to do is to get the aliens to follow them on field trips to try to introduce them to life on Earth. It's almost Christmas when they take the aliens to the mall to meet Santa, and finally, something happens, but what does it mean and why did they do it? Meg and an overworked, bystanding choir director wind up working together to try to figure it out.
It's very funny, and just a hoot to read. Entirely worth the three bucks to download it on your Kindle app. Sit down under the Christmas tree this week and spend an evening decoding alien behavior with Meg.