My partner and I each have our own little girls, mine is almost 5 and his daughter is 3. We've lived together for almost a year, and lately his daughters behaviour is taking it's toll on me. I've always been very strict with my daughter in relation to behaviour. Bad behaviour gets punished (naughty step, no treats etc) and i get extremely frustrated with my partner and how he just seems to ignore the bad things his daughter does. I've expressed to him how bad it is, and i got told 'i have too much of an opinion for something that's none of my business'. He would have her for the weekend and then just pop out for 10 minutes (more like an hour) to the shop and leave me babysitting. Which is no problem but when its his weekend with her and i've spent more time with her than he has then i've got a huge issue as i also want to spend more time with my daughter. I never ask him to look after my daughter simply so he can't throw it in my face to look after his daughter. Even just today he cooked us all an amazing roast dinner and she refused to eat it, he then offered her a yoghurt and i had to put my foot down as it goes against every single rule i've brought up my daughter (if you dont eat it all, no treat) and right in front of her face! I thought the no treat rule was BASIC parenting. She cried pretty much the whole meal and i had to get up twice and put her back up the table. We've argued before and he said he doesn't like to tell her off as he doesnt have her that much in which my reply was if you set the boundaries then she'll learn and you wont have to tell her anymore. I worry that my daughter is going to see him completely breaking the rules for his daughter. His daughter is so stroppy, moaning or crying every single time something doesn't go her way. Her tantrums are ridiculous and ive suggested him to just ignore her as when she's with me she never tantrums cause i blank her and carry on as though she's not there but she knows she can play daddy like a fiddle and he'll back down. Ive told him he needs to be more firm and PARENT her rather than being her friend as he really is making a rod for his own back and he's not the only one who has to deal with it. Im starting to regret having him move in as i cant even escape when i need to. Im starting to HATE the weekends he has her. We've also argued as he told me she slept through apart from when she is teething so i said she could go in with my daughter and they share a room but i've since told him no as so far she's been teething solidly for a year. i feel like the sleeping through was bullshit and my daughter has just started school so she is not being woken up by it. Im not saying my daughter is an angel as she has her moments. All days out are ruined and he recently suggested a holiday with the kids and i can literally think of NOTHING worse. His daughter runs away and he doesnt tell her off and just runs after her which is great until she runs into the road and gets hit by a car! If he could accept there was some work to be done i'd be happily help with no judgement but how can you help someone who sees no issue and has rose coloured glasses on?!