The co-stars of "Jon & Kate Plus 8," who are parents of sextuplets and twins, made their announcement on Monday's episode of the TLC reality series.

The network had promised a major on-air decision from the couple, whose increasingly troubled 10-year marriage has dominated the series in recent weeks as well as fueling a firestorm of tabloid coverage. Published accounts have alleged infidelity by both partners, accusations they both deny.

The Gosselins' announcement raises new questions about the future of "Jon & Kate," which, now in its fifth season, is TLC's most popular series.