Does a fiancée's frank disclosure to her fiancé of all situations she experiences, and all that she sees and hears, increase trust between them or arouse suspicions?

The suitor is a stranger to his fiancée before the marriage contract. Therefore, it is not permissible to discuss personal matters with him or to inform him of sins, because a Muslim is commanded to conceal their own sins. As for shyness, if it is within the bounds of legitimate modesty, it is commendable and a branch of faith. However, if it leads to neglecting duties, it is blameworthy, and one must overcome it by seeking Allah's help, by socializing with women in good conduct, and by enjoining what is right and forbidding what is wrong. Indeed, character is acquired through habituation.