Hi. I am about to fly with Singapore Airlines on a ticket that has 3 passengers. ( non refundable ticket) One passenger may be a no show at the last minute. The TA advises me that if I don't let her know before we get to the airport that it will compromise our flight back ( for the 2 that are going). Is this correct- or does a no show of one passenger just mean we may have a spare seat near us.