What do you all think of this situation:
My 23 year-old brother is always secretive about who he dates and actually hates posting on social medias. We didn't know much about his romantic life until recently. His gf of 6 months is my same age, 19 years old. However she's none other than my former classmate I haven't seen since 6th grade. I had her in my classes for 5th and 6th grade. I never thought I would see her again until that awkward moment last month. I didn't know how to react to be honest and was speechless. I've greeted her as if it was our first time. In a quick flashback to the past, let's just say my female friends and I knew her by another name I would rather not say and many things happened. I had a hard time looking her in the eyes during the reunion. For instance during lunch at the table, my brother explained how it's such a coincidence we went to the same grade school and what a shame that we never met each other; I kept with the lie and she secretly smiled and winked at me. She remembers me alright.

I felt nothing but embarrassment and shame during that whole meeting. Should I mention about the past, make amends or continue with the normal, adult conversations? She's the same girl I picked on every day at school when we were kids. I guess it's a small world after all.

Apologize to her in private sometime IMO.