public void DeleteRelationship( 
   Row originRow,
   Row destinationRow
)

public async Task DeletingARelationship()
{
  await ArcGIS.Desktop.Framework.Threading.Tasks.QueuedTask.Run(() =>
  {
    using (Geodatabase geodatabase = new Geodatabase(new DatabaseConnectionFile(new Uri("path\\to\\sde\\file"))))
    using (RelationshipClass relationshipClass = geodatabase.OpenDataset<RelationshipClass>("LocalGovernment.GDB.luCodeViolationHasInspections"))
    using (FeatureClass violationsFeatureClass = geodatabase.OpenDataset<FeatureClass>("LocalGovernment.GDB.luCodeViolation"))
    {
      QueryFilter queryFilter = new QueryFilter { WhereClause = "LOCDESC LIKE '%Jefferson%'" };

      using (RowCursor rowCursor = violationsFeatureClass.Search(queryFilter, false))
      {
        if (!rowCursor.MoveNext())
          return;

        using (Row jeffersonAveViolation = rowCursor.Current)
        {
          IReadOnlyList<Row> relatedDestinationRows = relationshipClass.GetRowsRelatedToOriginRows(new List<long> { jeffersonAveViolation.GetObjectID() });

          try
          {
            EditOperation editOperation = new EditOperation();
            editOperation.Callback(context =>
            {
              foreach (Row relatedDestinationRow in relatedDestinationRows)
              {
                try
                {
                  relationshipClass.DeleteRelationship(jeffersonAveViolation, relatedDestinationRow);
                }
                catch (GeodatabaseRelationshipClassException exception)
                {
                  Console.WriteLine(exception);
                }
              }
            }, relationshipClass);

            bool editResult = editOperation.Execute();
          }
          finally
          {
            foreach (Row row in relatedDestinationRows)
              row.Dispose();
          }
        }
      }
    }
  });
}