I'm so glad Aaron said that! he had a feeling they were going to announce an engagement that he never agreed to. What Keeley saw/heard just proves Aaron was right. I wish she would have just told him she ran into lacy and that's what she said.
If you really were over Aaron, Keeley, you would have considered a relationship with someone else. The fact that you still think about him and compare others to him, means you haven't moved on.