There's something besides the—familiarness that makes husbands dull.
mid-14c., "intimate, very friendly, on a family footing," from Old French famelier, from Latin familiaris "domestic, of a household;" also "familiar, intimate, friendly," dissimilated from *familialis, from familia (see family). The sense gradually broadened. Of things, from late 15c. The noun meaning "demon, evil spirit that answers one's call" is from 1580s.