Erotic love relationship needs

Bryan Weaver and Fiona Woollard seem to think that there are people whose needs for erotic companionship could not be met by one monogamous relationship. I hereby hypothesize that for all x, if x is such that his or her needs for erotic companionship could not be met by one monogamous relationship, then x is such that his or her needs for erotic companionship could not be met by any number of relationships.