I mean if you're gonna cheat why stay with the other person anyway ?
Breaking up is the best option .-. it free's b o t h of you. Which is why before you get into any sort of romantic relationship, you've gotta ask yourself, "Am I willing to be loyal for this person?" And if the answer is no, no matter how bad you feel, declining is the best way to go.
And for the people who stay with their partner just cuz of money or to increase popularity ._. or some any shit like that, thats just... f**king aliens, man. What is l o v e to these people.