There is no justification for choosing to cheat; it is a decision that one makes. And no matter how many times you apologize, it’s difficult to trust someone again after they’ve been disloyal.
A man, for instance, shared online how he struggled to believe his ex-girlfriend when she told him she was pregnant with his child. The guy explained how they had a great relationship until he discovered she had been cheating on him. The author sought advice online after the girl and her family tried convincing him to cover her maternity expenses.