Hero's Mom to Usher: Drop a Beat At My Son's Wedding, Please!

Usher is publicly thanking the men who saved his son from drowning in a pool this week ... but the mother of one of the heroes wants Usher to show his gratitude in a different way -- by becoming a wedding singer ... TMZ has learned.

The mother of Ben Crews -- the audio-video worker who pulled Usher Raymond V out of his great aunt's pool -- tells us her son is getting hitched next week, and she thinks it would be a nice gesture for Usher to sing at the wedding.

Mama Leigh Crews tells us Ben isn't expecting any money for his heroic deed -- but she says a tune or 2 would make his wedding unforgettable.

Usher released a statement saying "I would especially like to thank the two men who saved my son's life, Eugene Stachurski and Ben Crews. They are true heroes and I am deeply grateful to them."