There are two things that make a relationship work: Faith and Honesty. It is best to communication openly and honestly with your partner, while at the same time strengthen your relationship by remaining faithful to your better half.
But as humans, we are bound to commit errors. You may have cheated and feel sorry about it, but will you have the courage to tell that to your partner? Are you even supposed to tell your romantic partner that you cheated?
A magazine article on relationships stated that it would be better that you would not tell your partner if you had cheated because it would only add to the pain on both of you. Instead, the article suggested that you simply have to be remorseful for your actions and never do it again. In that way, there was no reason to divulge about being unfaithful.
However, why would you betray your partner not only by being unfaithful but also by being dishonest as well? Although your partner would be shocked to hear that you have cheated on her once, not to mention facing the risk of having your relationship ended, telling your partner the truth might also strengthen your bond once the initial shock has subsided. The revelation may serve as a wake-up call to both parties on what was not working in your romance.
Whichever decision you make, may it be for the betterment of your relationship, keeping it stronger and more romantic than the last time.