A coworker offered to treat me to lunch the other day at a nearby restaurant. I said yes, and we agreed to meet at my desk at our scheduled lunch time. When that time came, she was nowhere to be found. None of my coworkers knew where she was. I didn't want to wander around looking in case they showed up at my desk. I waited about 15 minutes before I assumed they had forgotten or gotten busy. I pulled out my lunch I had packed (we made the plans for lunch earlier that day so I had still brought mine) and sat down to at at my desk. Two bites into my sandwich, CW walks by with CW2, sees me, and says " Oh, you started eating." Before I could swallow my food, she says to CW2, "we'll, looks like it will just be the two of us for lunch," and walked away. It took like 10 seconds.
If I had a chance, I would have liked to have said "oh, it's just a sandwich, I'll put it away and we can go now. I wasn't sure if you forgot our plans." Would that have been okay? Or did her lack of apology/re-offer imply she doesn't actually want to go? Would it be okay to ask her if we can go later this week, or do I wait until she mentions it?