What to do?

As I was leaving school Friday night, I heard a student tell his mother that he had a "C" in every class. I didn't say anything, just kept walking. I had just told him that morning that he had a "D-" in one of my classes and an "F" in another. But I still didn't say anything because I was at the far end of the hallway and would have had to sprint down there, admit I was listening to their personal conversation, and it was Friday - 6 PM - I had just finished my grades and I wanted to go home. Besides, his mom is something else to deal with and it was Friday, I had nothing left that could possibly give me enough strength to do that. Conferences should be interesting.