<human>: Sorry for the throwaway and bad formatting, I'm on mobile. 

So my boyfriend and his family recently went to to Europe to see extended family. This included his mum, dad, himself, his friend, his brother and his wife and his other brother and his relatively new girlfriend. I unfortunately couldn't go as I had a unit at uni I needed to complete in order to graduate, also $$$. 
Obviously first up, seeing all the photos of them together popping up literally from each and every one of them was upsetting, but nothing I can do. The photos of all the boys and their partners was probably the worst, along with his mums caption - "I love my kids" or some shit. 
Anyway, after the first few weeks of them all being together, they all went their separate ways. My boyfriend is currently still in Europe travelling around, and everyone else is back home. 

We've been dating for over 4 years now, and I'm at his house nearly every day (he still lives with his parents) so I'm very close with them. Today was his mums birthday, and I assumed if anything was happening, I'd be told. 
I went on Facebook to see a whole album of pictures of a huge dinner, cake, wine, presents, all happening at their house with my bfs brother and wife present, and the new girlfriend (without brother bf who works away) 

Am I right to be upset about this? I mentioned it to my bf, trying to not sound too snide, and he said it's probably because he's not there - but that's exactly my point. Why does he have to be present for me to be invited? Why was this new girl invited? I'm feeling really upset because I love his family, and I make a huge effort with them and anything they're going through.

Can you condense the text into three sentences or less?
<bot>: Boyfriend and I have been dating for 4 years, very close with parents, didn't get invited to birthday dinner.