Agree. Maybe she is really bothered by university problems. But does not matter. She was not in the mood and everybody could see it. The result after it is no surprise then. And this action was so unnecessary. The whole party to that point was pretty cool and hot. But what followed was not okay at all.
The girl clearly was not in the mood and no matter if she was drunk, drugged or just did not want to the action really was not right. I believe that she loves sex but for sure did not want to in that particular moment. Letting her sleep til morning would have been the the right thing here.