Originally Posted by
PTravel
It is, indeed, the prerogative of the airline. Nothing in the OP, however, suggested that this was the case.
Nor does the aisle passenger using the middle seat in any way deprive the parent of what he/she paid for. Why would you think having a lap child invests a parent in superior rights?
I said nothing about superior rights, if you reread my post, I wrote about airline protocol. You were the one who presumed the parent was claiming superior rights when you said "just one more expression of parental entitlement" which seems to be an assumption without evidence concerning the parent's attitude.
OP has no way of knowing what the airline staff may have said to the parent, and based on what was posted, nothing was said within OP's hearing. However, that does not mean no offer was made to the parent about use of the empty seat prior to then. If the airline offered the seat to the parent, the aisle pax is not within his/her rights to deny it to the parent.
Just because the parent chose not to become confrontational does not mean the airline didn't offer parent & child use of the empty seat.