Anna Kournikova -- Ringer for Married Woman

Anna Kournikova posed with her little brother Friday, but all we see is that gigantic ring on her left finger that sure looks like she sealed the deal with Enrique Iglesias.

Rumors have circulated for years the 2 got hitched, but there's been no hard proof.

They've been together since 2001, so married or not, they've outlasted most celeb relationships.