Justin Timberlake Attended That Marine Corps Ball on Saturday

Remember that fad over the summer of American soldiers asking celebrities to attend their annual balls? Well, JUSTIN TIMBERLAKE came through on his promise, and attended the Marine Corps Ball in Richmond Virginia on Saturday.

This whole thing started when a Marine named Scott Moore invited MILA KUNIS to HIS ball. Justin told Mila she HAD TO accept . . . which opened the door for Corporal KELSEY DE SANTIS to ask Justin out.

Yesterday, Justin wrote about the "date" on his website. He called it, quote, "one of the most moving evenings I've ever had."

He added, quote, "[Kelsey] seemed to me to be so humble and honest . . . Very cool . . . Thank you Corporal Kelsey DeSantis. Thank you for inviting me. And, thank you for being my hero."