There's a big difference between having a mutually respectful conversation with your partner about how you'd like your child to move in - and discussing together every aspect of how that would work - before agreeing to give it a go ...... and somebody telling their partner that this is how things are going to be and if you don't like it "tough" because it's "none of your business, your opinion doesn't matter and it's up to me" - particularly when they're expecting you to act as the child's FT carer almost 24./7. Personally, I'd also think that such a momentous life change should be something that's also discussed between the child's mother and her partner - because there has to be a mutual agreed stance going forward between both parents (and their partners) so said child can't play one household off against the other - (potentially) bouncing between the two whenever she wants, e.g. to avoid punishment, to take advantage of what she sees as less firm "rules" and/or to punish whichever parent she feels aggrieved at that week.
I suspect the reason why Ginger has asked her DP to leave isn't because he wants his daughter to live with them but because of his appalling contemptuous attitude towards her. She's already experienced that when she was scapegoated for this child's lies but this week has reinforced how he really sees his partner.
As Wakey says however, less consideration seems to have been given to the situation than most people would regarding getting a goldfish and as Tutt's story illustrates this is the sort of thing where it's absolutely essential to cross as many t's and dot as many i's as you can possibly imagine before taking the next step. For everyone's sake.
If this story was the other way round I expect any sensible person would want to know the ins and outs of it before judging OP. If a woman expected her partner to take on - as in actually providing FT childcare - her children without any consideration towards his feelings or opinions, AND, spoke to him in such a disrespectful and dismissive manner, I'd feel just as angry towards her as I feel towards Ginger's DP. IMO the only double standards in this sorry tale are the DP's, NOT Ginger's and while I can't speak for other posters, I don't think my attitude to something like this would be different if it was a man complaining about the same thing either.
Anyway, debating all this is a bit of a moot point because Ginger's bravely decided to stand up for herself and do this alone. As I said before I feel his behaviour and attitude to her is practically emotionally abusive - she's certainly not treated as an equal as she should be - and that's good enough reason for them to split, not least so Ginger's kids don't grow up getting the message that it's okay for women to be treated like worthless chattels by (some) men. The SD issue has brought this to a head but I really don't think that specifically is why they're splitting up - he's not behaving like a loving supportive partner.