undutiful

He mourned for them afterwards, when he found I was not undutiful, as he had called me.

With a dispensation that would have been dutiful which he had done undutifully without one.

Henry was an undutiful son, and his reign was one long period of confusion, marked by incidents of the most ignominious kind.

I'm sorry to appear the undutiful grandson and all that, but really, don't you know, I must discourage her a bit.

Don't, Charles, it—it's ungenerous and undutiful to reproach me with being a shareholder when you know how innocently I became one!