Ali may have been a master manipulator, but she was still a child. The show loves to remind us that Ali "seduced" him or lied about her age. But legally and morally, the onus was on Ezra, the adult, to say no .
Ezra’s interest in Alison wasn't just romantic. He was researching her and her friends for a true crime book about her disappearance. Surveillance: alison and ezra pretty little liars
It’s never addressed. They share almost no screen time alone. The show simply banks on the fact that viewers have short memories or are too invested in Ezria to care. Ali may have been a master manipulator, but
Future analysis of Alison and Ezra's relationship could explore: Ezra’s interest in Alison wasn't just romantic
The fact that Ezra knew Alison was alive while letting Aria grieve—and while dating her—remains the darkest point of his character arc. It redefined their entire relationship as one built on a foundation of surveillance and lies rather than genuine fate. Their Dynamic in Later Seasons