Originally Posted by KebaNYC
Leave the BP with Mom.
You will preboard with the carseat, the FA will question whether you had purchased a seat (which they will assume that you didn't) and/or they will tell you in a semi-rude tone that you have to put it in the window seat.
The process should be very smooth. Only problem I ever have is that my wife does not wait long enough before boarding and baby (now 20 months) still spends extra unnecessary time on the plane.
Keba
Thanks for the help! I can hear it now...."you *gasp* bought a seat for your child when you could've flown with them for free on your lap going to BWI?"

Gotta love having rows of 3 on UA, and E+ no less! Hopefully we can have mom and baby wait until the last Group 4 pax are in line before strapping him in