Of course Christopher is upset about Daniella and Gemma's friendship because he was friends with Stephnie before the show. He has settled (for the moment) his differences from before he show with Daniella, but the Daniella and Gemma friendship is inconvenient for him.
Daniella knows that he will never criticise Stephanie because he is just as afraid of her as he is of Gemma.
Daniella has asked him why he always defends Stephanie and he admitted he is afraid to upset her because they socialise in Liverpool.
Some like him and see him as 'nice'.
I find him spineless