Boris Johnson has denied that the party took place, but hasn’t bothered to provide an alibi for the evening in question, so it looks likely that when firmer evidence emerges (as it surely will), he’ll frame it as a different kind of gathering. Probably not a ‘business meeting’, because Allegra Stratton has already chortled over that fib in the leaked clip, but some other euphemism. Like most antisocial behaviours, lying tends to be self-limiting: people who lie can’t cause harm for long because they lose credibility, and lying only works if people are inclined to believe you. But as with most things, Johnson is an exception to the rule. He lies effortlessly, without any apparent cognitive dissonance or regard for plausibility, and with little effect on his credibility or popularity.