Wife recently completed a DCA => IAH roundtrip. On the return leg and in the row ahead of her sat a mom and dad and a "lap child". Dad was ticketed for the aisle seat and mom was ticketed for the window seat. The proclaimed 2 year old (actually bigger and older according to my wife who knows about such things) sat on mom's lap until the aircraft door was secured. Then with the middle seat unoccupied, mom promptly deposited the child in the empty seat.

Wife was perturbed by the shenanigans of booking an aisle and window seat which usually leaves the middle seat open and then putting the kid there. I told her it was a creative solution but one that could quickly unravel if the plane is full.

The FAs weren't especially concerned as long as everyone was safely buckled in.

Has anyone else see this trick? It was a first heard for me.