obdurate
“adjective
unmoved by persuasion, pity, or tender feelings; stubborn; unyielding.
stubbornly resistant to moral influence; persistently impenitent: ...”
in flagrante delicto
“adverb
1. in the act of committing a misdeed
2. while performing sexual activity
Synonyms: red-handed
Etymology:
From Mediaeval Latin: ...”