In no way, shape or form do I take credit for creation or ownership of the Hagane no Renkinjutsushi (Fullmetal Alchemist) series. The original manga is the property of Hiromu Arakawa and the anime is the property of Bones animation studio.
Spoilers about Barry the Chopper's part of the story that is manga-only?
Jealousy:
The first thing Roy did when he realized he was jealous of Barry the Chopper was spit his coffee out all over his desk. Honestly, the idea was truly bizarre from any angle; to be jealous of a body-less murderer forced into hiding and unable to do the thing that he practically lived for was ridiculous at best. However, the more he thought about it, the more he had to admit it was true; he was extremely jealous.
After all, he wanted to be impervious to Riza's gunfire and able to freely declare out loud that he loved her too.