Sentence:  I think this is the easiest way to teach <WSD>compersion</WSD>, to immerse oneself in the unconditional approval of another person's pleasure. / We usually seek <WSD>compersion</WSD> in the context of our lover being sexual with another person, which can be very beautiful, but equally scary. / <WSD>Compersion</WSD> is the coveted secret elixer of emotions because it promises to turn the pain of jealousy into an ecstatic calm, or ecstatic release. 
Meaning of the word marked with <WSD> tags:  The feeling of vicarious joy associated with seeing one's sexual or romantic partner having another sexual or romantic relation that brings them joy, coined as antonym of (sexual or romantic) jealousy.