I'm looking for a story about two couples, each of which would like more spice in their sex life. They are attracted to swapping, but nervous about the consequences, so they settle for having within-couple sex together, getting excitement from each couple watching the other. Then they progress to swapping briefly and "warming up" their new partner for a while, before the couples swap again for within-couple sex. But, one night, the initial swap gets too exciting and the couples keep going on without switching back to their partners.
Any suggestions?
Any suggestions?
