She cheated on me but I forgave her. Then we get engaged and she cheated again, but she genuinely regrets it. Should I forgive again?

She sent dozens of paragraphs and hour long videos apologizing and insisting she made a mistake. She also says she will never do it agagain. The thing is, if I forgive her once, why not forgive her again? What's the difference? What if she was genuine because I really believe she does. She cried a ton of tears.