Being a Step-Dad

Hello,

I am a 30yr old male with 2 step kids aged 6 and 4. I have been with their Mum coming up to 4yrs and we recently got married (in August)
I'm looking for opinions as I've not really got anyone I feel comfortable to talk about my issues with face to face.
For the last few months, I've felt myself arguing with their Mum a lot and it's always because of the kids.
I regularly have this feeling that I'm not good enough. The kids always go to their Mum for everything. It's rare that they come to me unless I'm on my own with them. They wont even let me take them to bed. They always kick off if we say I'm taking them.
If they ask a question to their Mum and I answer, they will say 'no I'm talking to mummy' or if they need something doing I go to do it they quite often say 'no I want mummy to do it' or if they want to play their game they will say they want to 'play it with mummy'
This has pretty much always been the case and recently has really taken it's toll and makes me feel pretty low and I feel inadequate.
Do all kids tend to do this to some extent- lean towards their Mum and explicitly say they don't want their dad/step dad to help them or do I have grounds to be a bit upset about it?
I love their Mum and the kids but the constant rejection is making it difficult for me to keep it up. Is there anything I can do? I take them out and do things with them when it's just us but because of work, it's rare I have them on my own. Any advice is greatly appreciated.

Hi there, I am a step mum to a 10 year old boy. I am also a mum and a nan. I really think it is actually something children do, my grandson is 6 and his parents are still together, but he says to his Dad 'no I want mummy to do it' or '' I wasn't talking to you I was talking to mummy' he also does it to both his parents depending on his mood or especially with him how tired he is. ( He tends to want mummy more when tired) sounds like you are doing a great job and all you need to do is remember they are little children, it isn't personal and ultimately they just need to be loved. All the best