I attended the school prom on Saturday, April 17, 1999.

I went out with Chris Morris that night.

I knew Eric and Dylan to a decent extent.

Eric wasn't there. Dylan was though.

My last sighting of Dylan was, that he and the rest of us, left the school prom at 3:30 am in the morning.

Yes, the school prom wasn't over until 3:30 in the morning.

There was an "After Prom" that wasn't over until 5:00 in the morning, in which me and Chris Morris were still there and attended.