A gay sociopath I know put on great displays of jealousy if his target ever so much as mentioned another man. It was all hypocritical nonsense manufactured to flatter his target. The sociopath was seeing, hitting on and sleeping with other men all the way through, but knew that he would seem passionate if he put on a show of emotion, in the process convincing his target that he was his soulmate. If the sociopath feels any jealousy, it is that triggered by the potential loss of a possession and not a partner. Everything in his life is a performance, and he is the star.
For more on sociopaths and jealousy, read here.