Emily and Santiago are absolute masters in their fields, one the queen cockblocker, the other the king of not seeing something that is right in his face.
I have to put Ximena one step below, it takes her a while but after some time she recognizes the MC in the Gabi path, nothing on the Val path... but at least she's 1 out of 2.
Santiago, despite seeing pictures of this boy (old pictures granted), hearing his name, he was even announced as "MC Moreno", provided you win the race, and learning that he knows Emily... still fails to put 2 and 2 together

He does know the name of his son and that Andres surname is Moreno right?
He sets the bar pretty high... or low depending on your point of view.