"immoral behavior" is a correct and usable phrase in written English.
You can use it when referring to behavior that might be considered wrong, unethical, or otherwise not in line with moral standards. For example, "His immoral behavior was strongly condemned by his peers."
Post admits that THS may create criminal communities, where immoral behaviour and crimes are discussed openly.
Details of the allegations against him are sketchy, but officials say they involve "massive bribe-taking" and "immoral behaviour".
Distressed, Doria wrote to Puccini, saying that Fosca had plotted against her to cover her own immoral behaviour.
Emotions motivate moral (as well as immoral) behaviour, and they play an essential role in creativity and in scientific curiosity.
A St Petersburg district court has rejected a complaint from a gay teacher who was sacked for "immoral" behaviour.
Lately, though, the monks have been experiencing hostility as a result of numerous reports of immoral behaviour.
Nor would we regard a female schoolteacher who has an affair with one of her teenage pupils a paedophile, however immoral her behaviour – "sexual abuse" is often referred to, whereas the term "paedophile" is rarely employed.
Mayor Ansharullah is now working with Civil Service Police (Satpol PP) to eradicate what he sees as "immoral" LGBT behaviour in Padang.
And I'd say I've covered all the major bases: sex, ill-advised drug consumption, orgies, avalanches, immoral workplace behaviour, rich delinquents, Russian prostitutes – everything you'd expect when you mix young people with high altitudes.
They should be able to reveal immoral (but legal) behaviour by figures in the public eye if their behaviour contradicts their public pronouncements or could affect their ability to do their job.
Many Christians also rejected the literary traditions of the classical world, denouncing the immoral and unethical behaviour of the deities and heroes of ancient myth and literature.
