A personality condition in which someone uses feelings of "love" as a fuel source rather than a passion. People who suffer from Romantic Vamprism see love interests as outlets for attention, lust, confidence, and little more. Once their partner can't provide a needed amount of those things, they leave them behind for another victim. It's an addiction to the essence of love, not the details that make it last.
Romantic Vamprism is not easy to spot. Those who have it can be quite charming and outwardly appealing; it's their motive for love that gives them the condition. To them, a partner is a puppet for sexual and emotional energy, with little or no reason to keep them once they've served their purpose.
The "magnificent bastards" of heartbreaking, if you will.
"I'm in love with you!"
"Really now. I'm in love with your love."
"What about...you know...me?"
"Yes, yes, you too dear. I suppose. (For now...)"
Romantic Vamprism at it's finest.