I believe I’ve seen this question (or something similar here before) and I’m always intrigued by what people think.
My personal opinion — I don’t believe infidelities are equal. They all hurt and they all break trust, but the impact and the meaning behind them can be completely different depending on the situation.
Some A’s are short, impulsive lapses during a personal crisis. Others involve years of lying, emotional attachment, secrecy and severe gaslighting.
A few things that make a huge difference:
Duration — a one-night stand is not the same as a LTA or full blown double-life.
Depth of deception — hiding something is one thing; gaslighting, blame-shifting, or involving other people is another.
Emotional involvement — some A’s are purely physical; others involve deep attachment, maybe future-planning.
Risk-taking — unprotected sex, bringing the affair partner into shared spaces, financial spending, etc.
Their behavior during the A — some become cold, cruel, or distant, while others hide in shame.
Patterns — was this a one-time crisis, or have they cheated before.
I do think the biggest factor is who they become after discovery. That usually tells you more about the viability of reconciliation than the A itself. Are they taking responsibility and accountability, being transparent, doing the work, and showing empathy? Or are they defensive, minimizing, or hoping time alone will fix things?
Everyone’s threshold for pain, trauma, forgiveness, and rebuilding is different. Some people can work through even a LTA if the betrayer becomes accountable and truly changes. Others can’t move past even a "smaller" betrayal because it clashes with their values, boundaries and nervous system.
So no — infidelity isn’t equal. The betrayal might be universal, but how it affects you, what it reveals about the relationship, and what path you take afterward is deeply individual.