facetious Look up facetious at Dictionary.com
1592, from Fr. facétieux, from facétie "a joke," from L. facetia, from facetus "witty, elegant," of unknown origin, perhaps related to facis "torch." It implies a desire to be amusing, often intrusive or ill-timed. "Facetiæ in booksellers' catalogues, is, like curious, a euphemism for erotica." [Fowler]
erotic Look up erotic at Dictionary.com
1621 (implied in erotical), from Fr. érotique, from Gk. erotikos, from eros (gen. erotos) "sexual love" (see Eros). Eroticize is from 1914. Erotomaniac "one driven mad by passionate love" (sometimes also used in the sense of "nymphomaniac") is from 1858. Erotica (1854) is from Gk. neut. pl. of erotikos "amatory," from eros; originally a booksellers' catalogue heading.