Op, I totally know how you feel. I feel this way about my DD, and her dad doesn't even have a partner! It's all very well for people to talk about PR, but how does that work exactly at 3am when my child is calling for mummy or at 3pm, when she's having a pre-nursery meltdown? My DD sees her daddy for an average of 10 hours a week (and yes, he could see her more, I have never put restrictions on this, but he seems to have settled into this two afternoons a week routine because it suits him - I once asked him to look after her for a few hours on a Saturday night while I went out, which he did willingly, then deducted the corresponding hours from the maintenance he pays for her , I choose my 'babysitters' more carefully now) which leaves the rest of the time with me as the main parent. I organise her life, I pay for and ferry her to and from pre-school, I take her to the doctor, I know when she's outgrown her shoes and I buy her new ones, I deal with everything, good and bad, and my gut reaction to someone else encroaching on this territory would be the same as yours. Is it controlling? The way I see it is that many people love DD and could do almost just as good a job of looking after her as I do, but while I'm here they don't need to, it's my job and my privilege. I think if someone came along now and became DD's stepmom, I'd have the same issues as you, and that's without the horrible background you have with her (ex is still single two years on, I'm constantly expecting DD to pipe up with something about 'daddy's friend' but so far, no luck). But, having said all that, there's battles worth fighting and those that will save your sanity if left alone. If she took him to school begrudgingly and made him feel bad about putting her out, you have a case. Otherwise, just let this little thing go. I am speaking as a step child whose step mom hated me and made me feel like shit from age 11. She wanted my dad, but not his kids and she was a forceful woman. She banned my dad from any contact with me and my brother for five years when we were teenagers and we had to meet in secret. My lovely dad passed away last year and now she is in constant contact, sending gifts for DD, calling all the time. I feel sorry for her, but also a connection to my dad, and forgiveness, because I know that's what he'd have wanted. Sorry, lost the plot there, but am trying to say, if your DS has a decent stepmom in this woman, hard as it is for you, try to embrace it for his sake. I do see your issues with the school run, totally, as I have said, but try to save your energy for the bigger stuff. And I'm not looking forward to being in the position you are in now, but after two years, I'm sure it's just a matter of time before ex presents DD with a 'stepmom', and which point the poor woman will be vetted to within an inch of her life!