Definition: Given a real-life anecdote of a complex ethical situation, generate a suitable title that describes the main event/root cause of the situation. Imagine that the given text is a social media post, and you have to write the title of the post, so the users can decide to read the main text or not.
Input: For some background, I have been dating my girlfriend for about a year and a half.

It was my girlfriend's birthday on Friday. I had planned to suprise her that night with a dinner and cake at my place. She got off work early that day, and had made plans to catch up with one of her friends for a coffee to celebrate her birthday before coming over to my place. Her friend (who I will call Ally) was one of her longtime closest friends who now lives on the other side of the country for work, meaning they don't see each other very often.

Now I am not close to Ally, nor do I know her very well, but I have spoken to her before while they were on Skype, and she definitely knows that my girlfriend and I are together. Anyway, I am sitting at home on her birthday a few hours before she is coming over, and I get a text from her saying that she probably won't be able to make it to my place because Ally had organised a suprise birthday dinner for her.

Now I was a little annoyed since I had already bought the stuff to make dinner, but I hadn't cooked anything yet so no big deal. I texted back asking her what time everyone was getting there, and she said everyone was already there and it had already started. I said I would come and join them for dinner and she said that the reservation was only enough for the people who RSVP'd. I told her I hadn't heard about it which is why I didn't RSVP. I figured it could have just been a miscommunication, so I asked her to check with Ally.

I already know I'm probably an asshole for prodding as to why I didn't get invited, but I was just feeling a bit frustrated. A while later in the evening she texted me back that Ally didn't think to invite me because she doesn't really know me well and the dinner was supposed to be more of a get together of their old girl friends group from school. I was still a little annoyed that I had an evening organised, but I felt better knowing that it was more of a get together for her friends group.

I told her to have fun and arranged to meet her the next day to bring her birthday cake over. I didn't hear from her the rest of the night, so I texted her in the morning to ask how her night was. She said it was fun and that Ally would be joining us today for cake. I asked who ended being at the dinner. I was pretty upset to find out that on top of her old friends group, all of their partners attended the dinner, including Ally's fiance. 

Even more upsetting she said that one of her friends boyfriend who originally couldn't make it arrived later in the evening, and the server squeezed in an extra chair for them at the table. I asked why she didn't let me know when she saw this so I could come, and she said she just 'forgot'.

At this point I was pretty upset and I bailed on plans to see her that day. Mostly because I was angry at Ally for not telling me and I didn't want to talk to her, but also because I was upset at my girlfriend for not seeming to care that I wasn't there. I ended up eating most of the cake I made for her out of spite, which I feel bad about and know I shouldn't have done that.

We haven't really spoken much at all since yesterday, as she is spending today with Ally again before she fly's home. I am still feeling bad for bailing on her and eating the cake without her, and I might end up making her a new one. But at the same time I feel so annoyed that I was seemingly purposely not told about her party. This may be me sounding entitled but if anyone should have their SO invited to a suprise party it should be the birthday girl, and I kind of expect I should have been invited considering everyone else's partners got invited.

Am I the asshole?

tl;dr: Girlfriend had a suprise birthday dinner thrown for her and I wasn't invited, even though everyone else's partners were invited. Am I the asshole for expecting I should have been invited?

UPDATE 1: We have been texting each other and I told her I have been upset with the whole birthday situation. Ally and her fiance have gone back home and my girlfriend and I have agreed to meet up tomorrow sometime to talk things out

UPDATE 2: Sorry for the delayed update, was meaning to post it and I forgot.

I met up with my gf and we had a serious discussion about things. I told her I was not upset about her cancelling our plans for her birthday, I am upset about not being invited or informed by Ally, and I am quite hurt that she didn't seem to care that I wasn't there.

She agreed that Ally should have included me but defends her actions because she doesn't really know me and she already knows most of her other friends partners from school and before she moved away.

I told her I was upset because she didn't want me the there. She denied it and said she would have wanted me there but she felt it wasn't her place to go making demands at a party that was organised for her. she admitted she lied about forgetting to text me when the other guy showed up late because she was nervous about upsetting Ally and coming off as ungrateful.

I told her that it hurt me because I felt like I was unwanted at the party by everyone there, and that if she considers us a serious relationship I expect to at least be invited to these types of events that are special to her. She said she does consider us a serious relationship with a future together but did not realise something like this was such a big deal to me, and has promised moving forward to put me first in situations like this. I know she is particularly close to Ally so I can understand why she might have got all wrapped up with spending time with her.

I feel a lot better have talking it out with her, and I trust her so I believe that she means what she said. That said, the responses in this post pointed out some signs to look out for, and I will be keeping an eye out for any more of these in the future. I am optimistic that she truly means what she said and I believe if a situation like this happens in the future she would handle things differently. I am looking forward to continuing to build a future with her.

Thanks everyone for the responses.

expecting to be invited to my girlfriend's suprise party