That depends on the reason and sin the he/she committed. If the sin is unforgivable. Well there is no chance for the second time. But sometimes, we are not deserve the second chance at the same time. What I mean, a break up is needed in order for us to grow. Even the sin that committed is to hard to accept the apology. I remember this quote from one movie. [spoiler]You'll never think it is a mistake you chosen by your self that you choose to love your self a little bit more Passion inside, it's better to put to break up, so they can grown up thing grown up to make the relationship worth it.[/spoiler] Second chance can be made at the right time and at the right situation. Whether it is a test of love. even it takes time to prove it how you love each other. But most likely, giving a second chance for those who are not worthy is a mistake. The love you gave may not be the same way again. If he/she really deserve a second chance. Go for it. Remember, we are responsible for our own decision. Don't put any regrets if you have taken the same mistake.