Delia Cortez

The woman who scored an expensive condo, Bentley AND MORE from deceased L.A. Lakers owner Jerry Buss had clear instructions from the mogul -- KEEP QUIET about the relationship.Delia Cortez tells TMZ ... she started dating Jerry "years ago" when she lived in Marina del Rey, CA ... a beachside…

Jerry Buss -- who owned the L.A. Lakers before he died -- has given a girlfriend many decades younger than him an awesome parting gift -- his Honolulu, Hawaii condo and his 2009 Bentley! TMZ just obtained a copy of Jerry's will, and he leaves just about everything to his family trust. The trustee…