Beyonce: Backup Dancer Otherwise Engaged

Beyonce had a surprise for her dance captain Saturday night ... a big fat engagement ring!

Bey surprised the crap out of Ashley Everett, when she surrendered the mic to John Silver, one of her backup dancers. John sauntered over to dance captain Ashley Everett and popped the question.

It went down during Beyonce's Formation World Tour in St. Louis.

She said yes.