As a reader, I love subtext, those truths that seep through when we least expect it. As a writer, I love finding ways to ‘accidentally’ let them seep through.
Look for Freudian slips, double entendre, innuendo, ambiguity, insinuation, irony, connotation, denotation, and so on.
They often lead to comedy and/or horror as a character realises just what they have said or let slip. Just some of the fun you can have with words.