Answer:
It's disingenuous to search for a sentence with disingenuous.
He made several disingenuous promises during the campaign knowing full well that he could never fulfill them.
She offered a very disingenuous excuse for missing the holiday party.
The jury found her arguments to be very disingenuous and she was found guilty of the crime.
The prosecuting attorney lost the case because his leading witness came across as very disingenuous in the eyes of the jury.
His offer to take his son and daughter to the amusement park is quite disingenuous considering that he cancels outings with his kids all the time.