The phrase "straight laced" typically means uptight, rigid, or excessively formal. Antonyms for "straight laced" might include laid back, relaxed, carefree, or easygoing. Other antonyms might include casual, unconventional, free-spirited, or unconventional. People who are not "straight laced" may be more likely to have a sense of humor, be spontaneous, or enjoy taking risks. People who are more "straight laced" may be more focused, organized, and detail-oriented. Ultimately, whether to be straight laced or not is a matter of personal choice and preference, and everyone can benefit from incorporating a little of both into their lives from time to time.