Wiktionary
familiarity breeds contempt
prov. The more acquainted one becomes with a person, the more one knows about his or her shortcomings and, hence, the easier it is to dislike that person.
Usage examples of "familiarity breeds contempt".
Dennis knew because he was a butler's son from a long line of butlers, but familiarity breeds contempt, so they say, and he thought nothing much about the storeroom from which he fetched the napkins.