I should have left when Aiden showed up.

Ethan had texted me earlier in the evening — Movie night? Just us. I had thrown on a soft oversized sweater and a pair of short sleep shorts, pulled my hair into a loose knot, and driven over to his apartment without thinking twice. We had been doing this for years. Best friends since sophomore year of college.

Except nothing felt safe the moment I stepped inside and saw Aiden on the couch.

They were identical in almost every way — same dark hair, same sharp jaw, same broad shoulders — but I had always been able to tell them apart. Ethan...