Going Down

When the plane they're in is going down, Stan, Marv, and Meg all decide to confess their secrets before they die, including how Stan cheated on Meg with Marv, Meg is pregnant with Marv's kid, and Meg and Marv are brother and sister. After the plane straightens out, they all agree that it's not worth living with these awful secrets and collectively crash the plane.

Example of:
Deathbed Confession