What are these? They are similar and often used interchangeably; though the concepts are related, they are not identical. Both involve possession of something whether it is a treasured item, attribute or quality. The focus of attention in jealousy is a treasured item; the focus in envy is the rival who possesses the item.
Envy: I don't want you to have him.
Envy is the comparative evaluation of success through assessment of the success of a rival in which the envious person does not want the rival to have a treasured item or attribute. The treasured item may be tangible (spouse) or intangible (love), and it is often not the envier's target of desire but is rather a convenient item which will cause damage to the rival upon removal; the rival, not the envier, treasures the object. Though envy is often considered covetousness, it is not a requirement; the key feature is the desire that the rival not have the perceived advantage. The envious person may seek to seize the item for herself or simply remove it from the rival. Envy is a personal and deliberate act of malice against a rival.
Jealousy: You can't have him because he's mine.
Conversely, jealousy involves fear that a possession or perceived possession will be taken away. A jealous possessor is vigilant toward protecting her possessions or perceived possessions. Jealousy is not personal toward the rival. Notice that possession may be perceived, otherwise it would seem clear that spouses feel jealousy while OWs feel envy. But this is not always the case. Commonly MLCer OWs feel they are now the possessor of the MLCer and react with jealousy. Only OWs who direct their actions towards personally removing the MLCer from the spouse rather than possessing him for herself are envious. Such a person may also seek to possess the MLCer, but this is to cause jealousy and pain in the spouse rather than for a true desire to possess the MLCer.
In infidelity, envy seeks to replace. An envious OW wants to slip into the role of the wife, taking over her house, husband and life--it is both life and identity theft. This is the realm of the narcissist or antisocial person who is skilled at charming and conning. They are masters of disguise and confident impersonating different types of people. Jealousy in infidelity does not seek to replace, but instead seeks to possess and protect. A jealous OW steals an MLCer because in her view the spouse has lost her right of possession and possession has transferred to the OW.
Borderlines and histrionics are jealous, it is not their objective to be the LBS and have her life along with her husband; a borderlines desire is for the specific person that is the MLCer and a histrionics desires is for the attention provided by the person and relationship. Narcissists and antisocials are chameleons slipping naturally into various roles and identities. They are more likely to be envious than jealous. They want to take the positive lifestyle attributes of someone and destroy that person, such action is personal toward the LBS; an MLCer is merely a convenient prop.
The envious narcissist or antisocial may welcome contact and communication with the LBS for the purpose of torturing and taunting her with their superiority. Such an OW may act deliberately for the benefit of the LBSs attention. If an MLCer's affair is with such a person, it may continue as long as the OW feels she has the LBSs attention and power over her. This OW will publicly flaunt the relationship in front of the LBS or in public settings where the friends and acquaintances will notify the LBS. Without publicity there is no purpose in the relationship. An envious person is brazen, bold and certain in her superiority over the LBS--citing her relationship with the MLCer as proof.
In contrast, a borderline or histrionic is more likely to avoid contact or communication with the LBS whom she fears is better than herself and thus is overwhelmed with self doubts and the fear that the MLCer will return to the LBS, and if not the LBS, he will leave her for someone else. Where the envious person is open and confident, the jealous person is closed and doubting, though she is also like a mother bear protecting its young and will lash out if she feels her relationship is threatened. Jealous people resort to violence when they feel threatened and perceive their actions as defensive and justified.
Consider a situation in which an MLCer and his OW attend his child's sporting event; his wife, the child's mother also attends. The behaviour of the OW will differ depending on whether she is a jealous or envious type. The envious OW uses large or grandiose gestures of public affection toward the MLCer, continuously spying on the LBS to ensure they are being watched. The jealous OW keeps the MLCer close by her side. She may hold his arm or body tightly, but such clinging may go unnoticed by anyone other than the MLCer. She avoids the LBS. If she does approach the LBS it is a mother-bear angry, fearful and protective maneuver in defense of her territory.