It depends on who you ask. Men will likely to provide different answer than women. From a practical point of view the answer is simple. Cheating is cheating. Then nothing is simple in life.
For men physical cheating is more painful than emotional cheating because men relate to everything in a physical way first. Men can envision it- partner seeking comfort or escape in the arms of another. Men can’t grasp emotional cheating since men relate to everything to physical possessions.
For women, sexual indiscretion is not significant because in their mind when their partner has an emotional affair, the partner has already given up in their relationship. Women tend to equate the emotional bonding to love for each other. For women, forgiving and forgetting isn't an option when their partner has emotionally cheated. Women’s perception is that when partner doesn't want to be forgiven — they want out.
There is no question that emotional bonding may not begin with only satisfying physical gratification. It means you and your partner are at loss when you are not together. You long for your partner’s arrival or presence. It may have begun as friendship which gradually leads affairs of heart- which aren’t always physical but deep emotional bonding.
How you detect emotional bonding, you ask.
It is fair to say, that most friendship is likely to begin at your job or places you frequently visit- such as health club or bar. You are spending time with the friend too often. When you are not with your partner, you can’t wait until the next time you see each other. You can’t contain your inner inklings for your friend. You are pondering how it is to spend time with your friend. When something great happens in your life, you would prefer to share with the friend than your partner. When you are hiding your friendship from your partner then it is very likely an indication of your emotional involvement with your friend. Eventually, you will be ranting about your partner to the friend which can create an opening for emotional infidelity. What is even worse is that if you're wondering if you're having an emotional affair, you've probably already crossed the line.
Having feelings for another person does not make you a bad person. Sometimes, you can’t control your feelings, but you CAN control your actions. It is possible that you may wonder how your friend will feel if you opt to end the encounter. It does not matter because you need to ensure your partner is not affected by you.
In summary, men equate love to physical possession whereas women equate love to emotional possession. In the long run, emotional scars are likely to stay with you and affect your emotional state. Indeed, not pleasant nor worth it.