You never know how it is going to affect you until it happens to you. Love is the most powerful emotion we have as human beings, wars, have been waged over it, love lost is devastating, and is a form of torture when used in the manipulative hands of those that would wield it as a weapon. To be in love with someone, is to be open and vulnerable in a way no other emotion or intellectual sensibility demands, so when the betrayal occurs, it hits at the very core of ones existence, indeed the very core of our central nervous system.
The Ventral tegmentum, in which the seratonergic ganglion's of the Love response are centered in the brain, becomes hyperactive in cases where love is lost or unrequited, and the innervations with other areas of the brain, to do with pain, loss, depression and eating, are also seriously effected as they feed the intensity of the feelings of the person suffering the loss. Love is not to be played with, it deserves respect, sadly in our current cultural climate of excessive and convenient libidinous activity, sex has become king and Love seems to have been demoted.
We are no longer suprised by affairs, but its as well to consider, when your monkeying with another monkeys monkey, how it might feel if you were in love, and the same thing had happened to you.