I have heard of other fathers who will take the toddler / older child and leave the baby with their mum for the weekend for the same reasons - fear and feeling under-qualified to look after a baby. I always thought it was a shame but the mothers I spoke to were happy with it and were able to see that from a parcatical point of view their ex's weren't able to do hands-on baby stuff without them there showing them / teaching them. These dads were also waiting until the baby was more 'independant' (or walking and able to point at what they want and make themselves understood). I can see the practical sense of that now. I'd try not to worry too much about it or let it build into an issue or worry in your head because you're right - you don't want your children to sense that one is more importnat than the other. So if you get into your head that it's a practical solution and not a sign of loving one more than the other then this is what you'll be giving out to the children. However (always an however I'm afraid!)you're also picking up signs that your ex isn't interested in his daughter. You need to just keep an eye on it, relax about it at the moment as she's a baby, but just do little things and slowly in a non-pressured why that help keep her in dad's mind - 'could you keep an eye on her while I just help son do his teeth / get his stuff ready?', or 'look she's been trying to sit up / crawl / say something', 'we've had a funny morning haven't we on trying to feed daughter?! Tell daddy what happened!'. Nothing major just normalise it all and take the angst out. Just make sure that he's as familiar with her as he'll allow you to make him. And why do I think it'll be alright? because you have no formal arrangements and so he effectively chooses to see his son regularly - so, being an optimist, I can't see why he'd not want to see his daughter when he feels he can look after her properly. Good luck, Emily