Originally Posted by emcampbe

I doubt it.

When the second adult no shows, their reservation will be canceled. And someone else will likely be upgraded into the seat, and the return will be canceled (if this is the outbound). If there's no one on the upgrade list, and the seat remains empty....well, let's not get into completely unrealistic situations.

Since you can't change names on the reservation, you'll have to cancel the second adult (and assuming its non-refundable, you'll have the full ticket value to use for the canceled passenger on a future flight, once you pay the change fee). You'll need to buy a second seat for the infant (at going rate) if you want them to have a seat.

If you decide to keep the infant as a lap infant, you'll also want to make sure the infant is tied to your ticket, not the second adults, as that will cause issues that can potentially delay the flight if the second adult doesn't cancel in advance.