public IReadOnlyList<Row> GetRowsRelatedToDestinationRows( 
   IEnumerable<long> destinationObjectIDs
)

public async Task GettingRowsRelatedByRelationshipClass()
{
  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"))
    using (Table inspectionTable = geodatabase.OpenDataset<Table>("LocalGovernment.GDB.luCodeInspection"))
    {
      List<Row> jeffersonAveViolations = new List<Row>();
      QueryFilter queryFilter = new QueryFilter { WhereClause = "LOCDESC LIKE '%Jefferson%'" };

      using (RowCursor rowCursor = violationsFeatureClass.Search(queryFilter, false))
      {
        while (rowCursor.MoveNext())
        {
          jeffersonAveViolations.Add(rowCursor.Current);
        }
      }

      IReadOnlyList<Row> relatedOriginRows = null;
      IReadOnlyList<Row> relatedDestinationRows = null;

      try
      {
        QueryFilter filter = new QueryFilter { WhereClause = "ACTION = '1st Notice'" };

        using (Selection selection = inspectionTable.Select(filter, SelectionType.ObjectID, SelectionOption.Normal))
        {
          relatedOriginRows = relationshipClass.GetRowsRelatedToDestinationRows(selection.GetObjectIDs());
        }

        bool containsJeffersonAve = relatedOriginRows.Any(row => Convert.ToString(row["LOCDESC"]).Contains("Jefferson"));

        List<long> jeffersonAveViolationObjectIds = jeffersonAveViolations.Select(row => row.GetObjectID()).ToList();

        relatedDestinationRows = relationshipClass.GetRowsRelatedToOriginRows(jeffersonAveViolationObjectIds);
        bool hasFirstNoticeInspections = relatedDestinationRows.Any(row => Convert.ToString(row["ACTION"]).Contains("1st Notice"));
      }
      finally
      {
        Dispose(jeffersonAveViolations);
        Dispose(relatedOriginRows);
        Dispose(relatedDestinationRows);
      }
    }
  });
}

private static void Dispose(IEnumerable<Row> rows)
{
  foreach (Row row in rows)
    row.Dispose();
}