Banteringly

adv. [f. prec. + -LY².] In a bantering, jesting manner.

1863.  Mrs. C. Clarke, Shaks. Char., x. 258. Lavatch banteringly replies to his lady.

1883.  Harper’s Mag., Oct., 702/1. ‘Perhaps you intend to embark for Australia?’ she added, banteringly.