2 + 2 (2012)
Diego and Emilia swing with their friends Richard and Betina. Diego is hesitant about it, and he is right to feel that way, because later, Emilia starts seeing Richard without telling him and Betina.
Wife/GF Swap
Sex Games for Couples (1976) aka Fantaisies pour Couples – France
Two couples are cheating with each other’s spouses before having an official wife swap.
Wife Swap Diaries (2009) – Hentai
A wife swap that starts really hot turns surreal.