Ron and Hermione Tension

There was a part of Harry Potter that wasn’t clear – the tension between Ron and Hermione. You know, at the end of Chamber of Secrets (the movie), there’s this odd scene where when she comes back she hugs Harry and then has this strange interaction with Ron. Didn’t understand that at all, and Jieun explained there’s some tension between them or something like that. I didn’t get that from the movie at all.