<human>: I know this is silly and not as serious as 99% of the other posts on this sub but I need someone else's perspective.

So my gf of 3 years and I have pretty busy schedules and we really only have one day of the week that we can really hang out and go out and do whatever. So every week I look forward to this day and she told me she did too which is why I'm confused. 

Our free day to be with each other finally arrived so I thought I would pick her up and take her to have breakfast. It was going great until after we were done she said she had to get going because she was hanging out with her friend for the rest of the day. I like her friend by the way, and I don't mind them hanging out at all actually. What bothered me was that she didn't bothered to tell me she was doing that. Plus, they see each other three times a week in school. 

Her knowing that this was our only day to hang out and still choosing to hang out with her friend all day being able to do that other days is what bothered me. I hope I don't sound controlling I actually like that she spends time with her friends and all that, so do I. But that day of all days. And I would've been okay with it if she had just told me she wanted to hang out with her friend instead of telling me last know minute. 

I know I might be in the wrong and that's why I need another person's perspective.

Can you provide a brief overview of the text?
<bot>: my gf chose to hang out with her friend instead of me knowing it was the only day of the week we had together.