Four couples living in paradise experiment with bringing a third love into their relationships.

The Throuples' first challenge tests their boundaries, pushing some relationships to their limits.

The Throuples participate in their first "Stay or Swap" ceremony and make some huge decisions.

The Throuples face a test of core values; a new couple arrives, and nobody is off limits.

The Throuples engage in an honesty session; the resort's newest couple explores their options.

Big decisions rock the resort and leave some relationships questioning their Throuple.

The Throuples take part in a game to have some fun and get to know their chosen singles better.

As the end of the experiment looms, the couples go on dates to clear up unfinished business.

The Throuples face their final "Stay or Swap" decision, leading to confusion for some.

As the experiment comes to an end, the relationships face the ultimate question of commitment.