Cheating may not be uncommon in romantic relationships, but that doesn’t make it any less upsetting when it is experienced. One of the founding principles of any kind of partnership should be trust, and it can be hard to regain it when it is betrayed. Many would argue that you shouldn’t even bother trying to salvage a connection if your partner cheats.
On top of this, infidelity can be a difficult thing to experience even when you are not the victim of it. While the person who has been cheated on almost always has it hardest, if these actions break up an established relationship, they can have reverberations beyond just the couple themselves. Friends and family can find that they get drawn into the mess, whether they like it or not, making an already tough situation even more complicated. There is often copious potential for the drama to get worse.