Ketubot 9 - Claims
If the husband claims "I found an open opening" - that is, he felt that his wife was not a virgin, then he may not believed as far as the girl is concerned, but he is believed to impose a restriction on himself, and he now cannot live with her. This is the opinion of Rabbi Elazar. Others say that he would not be believed even for himself, since his feeling is subjective.
But according to Rabbi Elazar, even if we believe the husband's feeling, what evidence is there that she was unfaithful to him while being engaged? Perhaps this happened before engagement, and even if not, perhaps she is from a family where women do not have a significant hymen? - Rabbi Elazar's rules applies only in the case where one betrothed a girl when she was younger than three, and got married to her when she grew up.
Shmuel says that the husband is believed to the point that her Ketubah (marriage obligation paid in case of divorce) is void, and he does not have to pay it. But why would he be believed? Perhaps he is just trying to get out of his obligation? - Shmuel will reply that one would not trouble himself to make a wedding feast, only to loose her the next day.
Art: The Hesitant Betrothed by Auguste Toulmouche