Un-auntly

I vowed I’d take no responsibility for either of them, and as they didn’t seem to mind such un-auntly callousness, we got on well together and laughed our way across the Atlantic.

Source: wiktionary

Her petulant sister and the logy Luella never dreamed that Aunt Crete desired such un-auntly indulgences.

Source: wiktionary

Pronouncing Mrs. L. B. Parker’s conduct as “un-auntly,” Municipal Judge Hale this morning held her to the Grand Jury on $500 bond on a charge of embezzlement, preferred by her niece, Miss May Lindsley, a clerk in the Kress Department store, to whom Mrs. Parker refused to return clothing belonging to the young woman, on the contention that she had not paid her board bill.[…]His Honor and counsel for the defense of the “un-auntly” engaged in an argument over the proper disposal of the case and the rendition of the verdict, Judge Hale holding that the proper thing to do was to return the clothing and forget the whole affair.

Source: wiktionary

Humor is intended in the scenes where men make love to "her", and where "she" conducts herself in such an un-auntly way as to embarrass any respectable young man.

Source: wiktionary