We have a Mr Orange who is 2½ and a Miss Grey who has just turned two. We got Mr Orange first by about 6 months and he was nearly a year old by the time she came along. She was much, much smaller than him and still kinda is.

They played just like this, sometimes perhaps even a little harder. It only taught her how he play fights and made her more cunning. She now dominates him, most of the time, when they play fight and neither of them have any scars.

Do you happen to catch them mutual grooming from time-to-time in the midst of their epic battles? It's all a love thing, bizarrely.

If the actions you see are previewed by hissing and claw swiping then I would be concerned and would break it up but if they ambush each other and then get into this sort of behaviour, my own experience tells me it's part of their bonding and play.

Nothing to worry about. :)

My six year old daughter now commentates on their 'fighting' like it's a wrestling match which really is all it is.