If they are gonna cheat why did they got married in the first place, right? Hahaha. Because that dumb question gives the allusion that all people plan to cheat in the first place right? Even the ones who plan to cheat from the beginning of a relationship are very few. Or that all cheaters or relationships are alike, right? I've been on both sides of this situation.
Besides, when it comes to romantic relationships it's like a zoo out there. There are countless types and forms of relationships.
Some people commit in a relationship not just for love. Sometimes they do it because they think it's their only chance of happiness, due social approval, due to their old age, to please their lover (oh yeah, some people, in fact, play mind games, wanna trick you, threat you or give you an ultimatum to convince you into making a commitment) or because of the fear of abandonment. Sorry but this whole "people only commit because they love each other" is just a fairytale version for the smaller minds.
But he broke my heart, I have the right to burn his stuff, beat him and ridicule him. Yeah, sorry but no. You being heartbroken doesn't give you the right to abuse other people. Your feelings don't give you the right to take revenge against others. What if you're a bad boyfriend/girlfriend/spouse? What you think I'm gonna condemn other people because for finding happiness? And there's also the typical question, "if you're unhappy end the relationship instead of cheating". Yeah, because when you are in a relationship with a wicked person it's always so simple and clear to know what to do, right? A lousy lover never gets violent, try to manipulate you, or confuse you, right? You know all that romanticism that you claim cheaters step upon. Sometime they remain in the relationship because they have the romantic hope things get better. But none of that is gonna keep the world to stop turning and stop people from interacting with strangers and develop feelings towards them. With time, no relationship of any kind it's the same as when it began. So this idea that this person should feel the same towards you forever and if they don't, and they cheat, therefore should be punished, is dumb.
And spare me the whole: he/she swore me to be faithful speech. This may be a shocker for you but I gotta some news, people don't always keep their promises.
Being in a relationship means taking risks. The risk of getting hurt, the risk of getting cheated. This idea that once you secure the relationship, therefore, you won't have to worry about getting hurt is dumb. If you want safety and comfort then don't get involved in any relationship in the first place.