British actor famous for his sitcom roles such as Ralph Dring in Dear John, Michael in Agony and Dennis Dunstable in Please Sir and its spin-off The Fenn Street Gang. He also starred in the 1975 glam rock film Never Too Young to Rock. Peter John Denyer (20 August 1947 in Dartford – 18 September 2009 in Cheltenham) was an English actor who was perhaps best remembered for playing Dennis Dunstable in London Weekend Television's Please Sir!, and its spin-off series The Fenn Street Gang, taking on t ...