Would you not swear,
All you that see her, that she were a maid,
By these exterior shows? But she is none:
She knows the heat of a luxurious bed;
Her blush is guiltiness, not modesty. (IV.i.1670-1682)
Claudio humiliates Hero and himself in front of everyone, all because of a simple trick. He never further investigated the issue because he was impatient and assumes everything he hears is true. This was a big mistake that may lead him to future trust issues with Hero. Claudio is just one of the characters who gets the wrong idea about something, even though it might not be true. Two other characters, Benedick and Beatrice, end up falling in love because they trust whatever their friends say. At first, they are both set on never getting married.
Beatrice doesn't want to lose any of her free. At first, the two were just friends. Then when their friends start to tell them that the other one likes them, they begin to fantasize and fall for each other. Just like Beatrice, Benedick never thought about marrying until he hears that Beatrice loves him.
They say the lady is fair; 'tis a truth, I can bear them witness; and virtuous; 'tis so, I cannot reprove it; and wise, but for