Disclaimer: I do not, nor will I ever or have ever owned Full Metal Alchemist
--- Promise ---
War creates many things; enemies, friends and problems. But the war in Ishbal was different. Between a Major and a Private late one night by the edge of the camp, something more was created. A promise. A promise to work together to survive the war. A promise to stay together to correct the wrongs that plagued their lives. A promise to be loyal and honorable to the other no matter the cost. And even a promise to remain together, through rich or poor, sickness and health, even after death takes them apart. Roy and Riza will never break that promise.
A/N - A promise is very sacred, especially when it is as important as theirs.