As strange as it sounds, I went to school with a girl that did the same thing with her best friend. Neither were gay or Bi-curious, and never 'made out' with each other. They would masturbate themselves in the same room, or on the bed at the same time.... Hot!!!!
I love this series and this is my favourite. I smiled throughout even though it was so horny they seemed to be having such a "nice time" together. In the real world I am sure they would have been all over each other...but they stuck to the script and got the job done.
Don't get better than that.