Thanks for your replies, you have all really made me think.
There is obviouisly some history here: my ex's (childless) wife took to 'parenting' my late teen kids with gusto, using her considerable power to elbow me out of the way. I tried to tell myself that at least she wasn't wicked but tbh in many ways she has been by doing all she could to separate them from their mother. She hasn't been ultimately successful but she has made things very difficult for us, all in all.
That's my story and everyone's story is different. It's not hard to notice that people who have contributed who are stepparents have had a strong response to my OP, even though I was careful in the wording of it.
here's what I think: I think that the role of a step-parent is an unsung, selfless role. I think you put in all the grit and the commitment, up to a point, but at the end of the day that doesn't earn you a place in the childrens' lives, doesn't earn you a title - in fact, you don't earn anything. You can put all that in and still have nothing at the end of it. imo you do it for the love of their real parent (ie your partner), the children are indeed part of the package and you do the decent thing, for the greater good, but it in no way gives you a right to anything at all. I know that's unpalatable and it's not said in bitterness or malice: imo that is how it goes when you marry/partner someone who already has children - you ultimately take a back seat. If the relationships go well and you grow to genuinely love and respect one another then bravo, wonderful to have as many adults as possible genuinely committed to loving our children and acting as role models. imo that is a bonus but I don't think it is a given or a right, regardless how much sacrifice you may have made.
That said, I am not a step-parent! I am fully aware that it could be different if I ever am one, I may see things differently? What I do know is that if I ever was a 'step parent', I know down to my bones the dos and don't: that you don't step (arf arf) on the bio parents' toes, that you don't take on a role as though you have a right to it just because you married their parent. imo you don't have a right to a recognised relationship with the kids that aren't biologically yours, regardless how much graft and sacrifice you put in.
I meant to c&p an earlier post but lost it in the ether somewhere, but the term 'random woman' stuck in my head. That's how it felt to us (me and my kids): that a random woman appeared from nowhere, swung into taking a parenting role in their lives - disregarding me or them - which left us all open-mouthed. You mind your ps&qs if you take on children who are not yours imo and there is no guarantee at all that it'll turn out well, and neither can you expect it.
I'm sorry if my opinions offend - I don't mean to offend. I've obviously been chewed up by this whole thing and no doubt many step parents have been too. i recognise that many (most?) step parents are unsung heroes but, as I said earlier, I do believe that is par for the course I'm afraid.