to find annoying and weird my ex views his time with our kids as family time with new gf!

[frazzleoff]

it's that in a nutshell.
As background our kids are 5 and 7 we split up exactly a year ago - I found out he was cheating, again. Posing as a single dad. The kids have always been part of his M.O for attracting women :(
I think it's a way of making a bond with a girlfriend seem more real and permanent.
He is onto his 3rd 'girlfriend' and first real relationship but from the outset introduced her to the kids and any time the kids spend with him they are always together. As he did with previous short term girlfriends.

They usually stay at her flat or she will go to stay at his because he has the kids. And do everything together. So basically the kids never have his undivided attention. He is in my opinion mostly keen to present himself as superdad to impress his girlfriend.
And I feel it's unfair on the kids that they have this new family situation foisted upon them.
I do also suspect he is sharing the burden as he feels it of childcare!

Also to get in perspective - he only sees the kids every other weekend and will often refuse to have them if something else comes up (social events not work!) so sometimes will see them only once in a month.

I have also had a brief relationship/ still friendship with old old flame and did introduce him to kids after couple months, simply because lack of childcare led to us spending evenings at home etc but I managed relationship time around kids routines and never took the step of declaring us all a new family and spending a lot of time together with kids.

Am I being unreasonable or is it just normal that my ex wants to spend every minute that he has with the kids, also with his girlfriend?

In my experience it will backfire on him spectacularly when they are older. It only took till my DD was 10.

YANBU but there is nothing you can do about it. You can't dictate who he sees and you can't stop him introducing the kids.
Thing is the kids will wise up to it quickly and know that none of these women stick around long and will soon just ignore them/write them off as I did with my mothers boyfriends. They didn't hold any place in my heart or family and even though I interacted with them, went out and had days out with them, I had no interest in even knowing their names.

oh but that's awful too - I want my girls to come hardened :(

I want him to cherish his time with them and be a good father.

should say i don't want my girls to become hardened!!

Sadly they will do you can't change this or his behaviour. Focus your energies on your time with them and o the best you can.

I am in a similar situation, I have just recently introduced my DS to my new BF since parting from his dad. I have been with this guy for over 6 months and they have just met. They get on brilliant and seem to like each other's company. We plan to have a day out once a month the three of us then other days out/activities will just be me and my DS. My BF will also pop in for a cuppa or sometimes have dinner with us. He hasn't stayed over night and I don't plan on having him overnight with my DS here for some time yet. My DS is 5 and as long as he is happy with everything then so am I. My ex hates it but I see it as his problem.