Displeasing the parents

[michael313]

In the name of Allah, the Most Beneficent, the Most Merciful
And All praises due to Allah, Lord of the Worlds,
May Allah Send His Peace and Blessings upon Mohammed and the Family of Mohammed, the Imams and the Mahdis,

Religion has taught us that displeasing the parents is a sin. But if children are displeased with their parents due to parents' mistreatment with them and eventually react in such way that the parents get annoyed/displeased then will it be count as a sin? What is the threshold level of tolerance for adult children to get annoyed with their parents? Are children allowed to express any kind of anger or frustration to their parents? If they should not behave in such manners in any circumstances then what is the right way to express/channel their frustrations about their parents?

Please forgive my shortcomings dear Master.