What's monogamy got to do with love? We assume they go together but how important really is sexual exclusivity? And what happens when couples challenge this ideal?
Around the world people have different rules for their relationships - rules often dictated by culture and religion. In many societies the most important of these is sexual fidelity - true love and monogamy are expected to go hand in hand - but why should love mean forsaking all others? And what happens to relationships when monogamy is cast adrift?
(Image of couples kissing and celebrating the eve of Valentine's Day. Credit: Getty Images)