Amy seems to realize Iruma is human and then mostly doesn’t expose him ; instead, she keeps acting on her feelings and lets the relationship continue. The fandom consensus in the sources I found is that she “knows” or has strongly figured it out, but chooses not to push the issue.

What happens next

  • She puts off investigating it further.
  • She continues treating Iruma normally, with her feelings getting stronger.
  • The secrecy stays intact for a while, so the story keeps the tension around who knows what.

In fandom terms

A lot of discussion frames this as Amy/Ameri basically going: “Yes, he’s human… and I care more about Iruma than the secret.” Some fans also describe it as her quietly “playing dumb” rather than confronting him directly.

Simple takeaway

After Amy finds out Iruma is human, nothing dramatic happens immediately in her behavior toward him; she mostly keeps the secret and keeps growing closer to him.

TL;DR: she figures it out, doesn’t out him, and the relationship just keeps developing.