I guess many of us have experienced it. The moment that you understand that "the person you love, in whom you've trusted, is now with someone else, enjoying every moment with him/her".
It's so widespread that it might not be inaccurate that if we say that more than half of the people on Earth would experience it, and it's a universal feeling which is not dependent on race, culture and education.
However, apart from those presumptions, what I've felt during those moments was:
- Great pain (maybe not even pain, an instability) in the stomach, below the diaphragm
- The feeling of insecurity, as if everything is frightening
- No interest in anything, and I mean ANYTHING at all. No interest in food, in entertainments, music, even sex, nothing.
- Coldness in my extremities
I wonder if cognitive sciences have ever conducted a research on this subject or not. For example, which neurotransmitters are active in creating this feeling? What hormones are in action? Which part of the brain is responsible for the feelings related to infidelity? How can we treat it using medications, or other scientific methods, not fatherly advices.