Half-Life of a relationship is the time necessary to get over a breakup as expressed as a percentage of the total length of time of the relationship. For example some people take about 1/3 the time the entire relationship lasted for the sense of loss to finally resolve. Concept comes from nuclear physics where the half-life of radioactive material to become less toxic as expressed as a time value from the exposure (breakup) to the radioactive material.
“Man, I dated her for a whole year, and we broke up. It seems from experience that my half-life of the relationship will be about 4 months!”

“Dude, that’s too long, my half-life of a relationship to get over a chick is only 1/5 of the time we were together.”
by Zagorzan November 28, 2019
Get the Half-Life of a Relationship mug.