There are several synonyms for the phrase "be straight." Some of the most common and frequently used include "be honest," "be forthright," "be sincere," "be truthful," and "be candid." These phrases all indicate a desire for transparency and open communication, and can be used in a variety of contexts, from personal relationships to professional settings. Other synonyms for "be straight" might include "don't beat around the bush," "be upfront," "be direct," or "tell it like it is." Whatever the phrase used, the sentiment remains the same: a request for clear and honest communication.