Insipidity

Manners were not flagitious, they were merely of a nauseous insipidity.

Source: tatoeba (10656939)

You're beautiful to the point of insipidity!

Source: tatoeba (13368032)

1735, Alexander Pope, The Dunciad, Book I, Notes Variorum, in The Works of Mr. Alexander Pope, Volume 2, London: Lawton Gilliver, p. 98, Nahum Tate was Poet Laureate, a cold writer, of no invention, but sometimes translated tolerably when befriended by Mr. Dryden. In his second part of Absalom and Achitophel are above two hundred admirable lines together of that great hand, which strongly shine through the insipidity of the rest.

Source: wiktionary

Her complexion was sallow; and her features small, without beauty, and naturally without expression; but a lucky contraction of the brow had rescued her countenance from the disgrace of insipidity, by giving it the strong characters of pride and ill nature.

Source: wiktionary