He smiled ostentatiously to show himself reasonable and nice.
’I couldn’t agree with you more, sir,’ he assented briskly in a tone of ostentatious disapproval.
There was none of that crude, ugly ostentation about dying that was so common outside the hospital.
…herself about to the synthetic jitterbug music with more uninhibited pleasure than he had ever observed until he felt his legs falling asleep with boredom and yanked her off the dance floor toward the table at which the girl he should have been screwing was still sitting tipsily with one hand around Aarfy’s neck, her orange satin blouse still hanging open slovenly below her full white lacy brassiere as she made dirty sex talk ostentatiously with Huple, Orr, Kid Sampson and Hungry Joe.
There are no more uses of "ostentatious" in the book.