I felt that it was irresponsible to advocate the legalisation of drugs.

我认为鼓吹毒品合法化是不负责任的行为。

It would be irresponsible of me not to advise my company to abandon this project.

若我不建议公司放弃这个项目，那我就是不负责任。

Many people have an irresponsible attitude towards marriage and relationships.

很多人对婚姻与两性关系持一种不负责任的态度。