They PAID FOR THE SEAT!........................
You can go buy a whole plane full of tickets....and you will have to have them ticketed in names that have valid ID’s.
You cannot then give away those seats/tickets to whomever you choose....just because you paid for those tickets.
If those listed as the ORIGINAL ticket holder (in this case, the 18 year old son) don’t show for the flight, you cannot decide who gets to sit in those seats, just because you paid for the tickets.
It’s clearly listed on airline tickets....ONLY named passenger, for EACH ticket, may use the ticket.
Sorry. I promise to look and think before I leap the next time. Meanwhile, could someone hand me a rope down here at the bottom of this pit?