Charles Napier, 67, is accused of one count of inciting a child to commit an act of gross indecency. He is the half-brother of Maldon MP John Whittingdale.
Richard Alston, 69, is accused of five counts of indecent assault and three counts of gross indecency.
The charges date back to the 1970s at a London school.
Napier, of Sherborne, Dorset, and Alston, of Bury St Edmunds, Suffolk, attended Southwark Crown Court yesterday. Their conditional bail was renewed.