What does it mean when a rabbit mounts another rabbit on the face?

I have two rabbits, both female and not spayed. I bought the second rabbit to keep the first rabbit company. I quarantined the new rabbit for about a month before introducing it to the second one for the first time today. The older rabbit mounted the younger one's face and it looked like it was humping the younger one. When we tried pulling the older one off, she had pulled off some hair from the younger one. This happened several more times, and the younger one will always be lying down in a submissive position before the older one mounts it, as if she knows it's coming. Can anyone explain what this might mean? Is the older one trying to establish dominance? Thanks in advance.

The oldest one is attempting to establish dominance. it's saying "i'm older, i'm smarter, i was here first and I rule"I strongly suggest getting both bunnies spayed. Spaying alters their behavior and takes away a lot of aggressive behaviors. It's also the best thing that you can do for your bunny healthwise. Introduce them slowly to each other, and in neutral territory if possible so that your older bunny doesn't feel that the new one is moving in on her territory. Two females are very difficult to bond together. It will take time and they need to "date" for lack of better word. Let them play for a few minutes every day, and every day increasing the amount of time they are together. DO NOT LEAVE THEM ALONE DURING THIS TIME. Check out Rabbit.org, it has great info on spaying and bonding!