It would have been pretty difficult to write a situation that got Lena to go with Seymour, especially if she had been adamentaly opposed to Seymour.
I was surprised that EK chose to just skip over the rest of the vacation instead of doing an extended Lena POV of the beach house, especially since a lot of interesting developments happened that weren’t seen in Ian’s POV (i.e, Lena’s conversation with Wade)