When the Kennedy administration politically alienated
Frank Sinatra in 1962 due to the singer's ties with the Mafia, Sinatra blamed Peter and severed their friendship permanently. Peter was supposed to appear in the Rat Pack movie
Robin and the 7 Hoods (1964). Peter was replaced by
Bing Crosby. In later years, when Lawford decided to attend Sinatra's Las Vegas performance at Caeser's Palace in an attempt to call a truce, Sinatra reportedly found out about it and refused to go on until after Lawford had been escorted out of the showroom.