"President Biden got a visit from a Christmas troll Friday when a father participating in the annual White House NORAD Santa-tracking call used the phrase “Let’s Go Brandon,” the slangy stand-in for “F— Joe Biden.”
The dad, identified only as Jared from Oregon, wished the president and first lady Jill Biden a merry Christmas before adding the anti-Biden phrase at the end of his family’s portion of the call.
“Merry Christmas and let’s go Brandon,” the father said as he signed off.
“Let’s go Brandon, I agree,” Biden said without missing a beat.
It was unclear from Biden’s reaction if he knew what the phrase meant."
https://nypost.com/2021/12/24/biden-says-i-agree-when-dad-drops-lets-go-brandon-on-call/
This turned out to be the best birthday ever.