Apologies for the length of this one, but didn't want to drip feed...
My DB and SIL moved to New Zealand last October, and my niece was born on Sunday. I'm really pleased for them, and looking forward to meeting her.
My parents went out to visit them in January, her parents have been out twice but for flying visits en route elsewhere (they travel a lot with work so get lots of air miles). Her parents are going out in November and December, and mine were due to go in January.
I've been scrimping and saving for a year to go out there and finally booked my flight last month. I'm going in February for 3 weeks, and have lots of plans to stay overnight and do a bit of travelling elsewhere so everything is staggered and managable for them (all this is with their knowledge and approval - I'm very close to them).
Last night I got an email from my DB to say 'Isn't it great, mum and dad are coming out so they overlap with you, we can all have a family holiday'. I was a bit
, but thought 'Ok, a week or so, it'll be fine'
Turns out it's for 12 days, and my mum says 'us being able to have a family holiday makes up for not being able to see the baby for so long'. I was a bit upset, but rationalised that he's got other things on his mind that 12 days isn't so bad, really...I do get on with my mum (most of the time).
This morning I got an email from SIL's brother to say 'Hey, isn't it great, we spoke to New Zealand last night, and we're coming over just after your parents leave and we'll be there whilst you are. We knew you wouldn't mind so we booked it.' 
I checked the dates and this means I get less than 24 hours with my DB and SIL, the rest of the time other people will be there. I'm really hacked off at the assumption that I'll be fine with it, I'm not, I wanted that time with my DB and his family.
I'm not meaning to come across as totally selfish, but AIBU? Just feel like my whole time with them has been hijacked.