In 1963 John Profumo lied to the House that he had not had a sexual relationship with Christine Keeler. Once it became obvious that he had, and she had been having a similar relationship with the Russian spy Yevgeny Ivanov, it was obvious that pillow talk could endanger national security. Profumo resigned, and within months it helped to bring down the Tory government of Harold Macmillan. Today Johnson seems to wear his lies as a badge of honour, but there are rumblings going on about his relationships with Russians, which could make him a risk, as was Profumo.
The public, quite rightly, see Corbyn and his cronies as the real risk to national security.
Boris on the other hand is becoming more popular than ever, but it's lots of bad news for Corbyn (again).