Looking for advice... I have DD6 and DP has 2 DC. DSS 6 AND DSD 4.
They're both great kids and I love spending time with them, however we are a relatively new blended family and we try to spend time together as a group and we also esure that we do things independently too.
We introduced the DC at the beginning of the year and all went swimmingly for the first few months.
As we get further in my DD and DSS have started to bicker insestuently. They'd bicker one has had more air than the other if we let them. 
I appreciate they are a similar age and this is still a transitional period for us all but I'd love to hear advice on how others have dealt with this, if at all.
If I hear "it's not fair" one more time I'm going to quietly implode lol.
For context they all get treated equally when together, and are given choices in activities, brought the same sweets, given the same amount of pocket money and the same amount of chores etc.
Until now I never realised a specific seat on a rounded table was something so important it requires bickering over! 
I'm just looking for suggestions on how to combat this before it becomes a problem and turns into something else.
Thanks