<human>: I'll make this as quick as possible. So my gf and I had plans to hang out tonight after she gets out of work. I just texted her asking what time I should expect to pick her up at.
To which she replies, "Steph texted and asked if I could do something with her tonight...is that ok?"

I was kind of irritated by this since we had plans (she also has a hard time saying no to people and also worries way too much about if people are mad at her... Although it feels like I am exception to this rule.), but I don't want to be "that guy". So I responded, " Well.. We had plans. But you can do what you want"

Of course the reply to that was, "are you mad at me?"

I'm not sure where to go from here. Should I be irritated by this?

Summarize the given text in a few sentences.
<bot>: GF makes plans with me just to later tell me that her friend wants to hang out with her. Should I be irritated?