I was sick of these ungrateful children not paying attention to what I was saying.我讨厌那些不认真听我说话的不知好歹的孩子。

I don't want to sound ungrateful.我不想说薄情寡义的话。

You ungrateful brat.你这个没良心的小坏蛋。

I thought it was rather ungrateful.我觉得这样做太忘恩负义了。