Use "fatuity" in a sentence

1. This conviction was strengthened by his vanity and conceit, a conceit to the point of fatuity

2. He was inordinately homely: the prettiest boot-stitcher of that day, Irma Boissy, enraged with his homeliness, pronounced sentence on him as follows: "Grantaire is impossible"; but Grantaire's fatuity was not to be disconcerted