tongue-in-cheek

1. cleverly amusing in tone

    e.g. a bantering tone
           facetious remarks
           tongue-in-cheek advice

    Synonym: bantering facetious

1. not seriously

    e.g. I meant it facetiously

    Synonym: facetiously jokingly

2. in a bantering fashion

    e.g. he spoke to her banteringly

    Synonym: banteringly