Swapping partners in sex life has become a new way of enjoying married life adding more pleasure.
Supporters argue that we need variety in life (including sex life).
Talking of food, we do not like to eat the same dish every day, change of dish adds to the pleasure of eating.
Similarly, in sex life, once the couples talk to each other and understand the feelings of their partners swapping partners can be fun and enjoyable.
Do not use the phrase 'Wife Swapping'. 'Swapping Partners' makes more sense because it involves swapping husbands also.
Swapping partners has picked up in India also.