The other day, I approached two girls and chatted them up a bit. Though I was only interested in one of them, I didn't want to make it awkward for the other one, so I got both of their numbers. I only texted the one I am into, though.

I was busy last week, so I traded a couple of texts with her, and told her I'd text her closer to next week, when I'd be less busy.

I texted her a couple of days ago, asking if she wanted to grab some drinks.

Her response: "Yea, did you let [other friend] know as well ?"

So, clearly she's interpreting this as a friend outing.

Should I just go with the flow and invite both of them? Or should I exclude the other girl and make it a date?