This kind of goes with the other loud question, but if she’s just generally being loud and embarrassing the whole time, that would totally kill the mood for me too. Like, is she doing too much to try and impress you or act like a movie star? It’s hard to enjoy yourself when you’re constantly shushing someone or worrying that the cops are gonna get called for a noise complaint.
It makes it feel less real and more like a performance, which is honestly really cringe. You want it to be a special connection between you two, not a Broadway show that the whole neighborhood gets tickets to. It’s totally valid that you feel embarrassed because nobody wants to be “those loud neighbors” that everybody complains about.
You just gotta be real with her and tell her that she doesn’t need to put on a show for you. Tell her that being quiet and intimate is way better than screaming like a wild animal. If she takes it as an insult, just explain that you just want to keep your private life private, and hopefully she’ll understand and tone it down.