flagrante

in flagrante (delicto)

In the act of committing a crime, misdeed, or immoral act, especially having sex with someone other than one's spouse. I heard that he was fired after being caught in flagrante delicto with the new intern.
See also: flagrante
Farlex Dictionary of Idioms.

in flaˈgrante (delicto)

(from Latin, literary or humorous) if somebody is found or caught in flagrante, they are discovered doing something that they should not be doing, especially having sex: One of the gentlemen was caught in flagrante with the wife of the club’s President, which of course caused a huge scandal.
The meaning of the Latin phrase is ‘in the heat (of the crime)’.
See also: flagrante
Farlex Partner Idioms Dictionary
See also:
  • delicto
  • in flagrante
  • in flagrante (delicto)
  • blow job
  • keep up an act
  • keep up the act
  • act (up)on (something)
  • act on
  • acting
  • keep an act up
References in periodicals archive
Obviously, Sally barged in and caught them in flagrante.
La Minusma, qui a condamne les combats survenus dans le nord du Mali, [beaucoup moins que] en violation flagrante [beaucoup plus grand que] du cessez-le-feu dans la region de Kidal, a invite les parties concernees [beaucoup moins que] a s'inscrire dans les arrangements securitaires dans l'accord de paix d'Alger [beaucoup plus grand que].
Mind you, Mark wouldn't be the first man to come home unexpectedly and find his wife in flagrante delicto.
[beaucoup moins que] Cet acte est une violation flagrante et inacceptable des lois et normes internationales qui garantissent la securite des fonctionnaires et des missions diplomatiques et consulaires [beaucoup plus grand que], a indique Benali Cherif dans une declaration a l'APS.
Studio moguls are hard-headed ruthless tycoons who wouldn't care if their "talent" was caught in flagrante delicto with King Kong, so long as they put bums on seats.