Proverbs 10:23 states that a fool treats wrongdoing as a joke — exactly what the deceiver does when he says 'I am only joking'.

Proverbs 15:21 observes that folly brings joy to the senseless — the deceiver here delights in his foolish joke.

Proverbs 14:9 says fools mock at sin — parallels the deceiver who mocks his neighbor by calling his deceit a joke.

Ephesians 5:4 warns against crude joking — directly relevant to the deceiver who uses 'just joking' to excuse harmful deception.

In 2 Peter 2:13, those who 'sport themselves with their own deceivings' parallels the man who deceives as a joke — both condemn malicious play.