"You know I live here," Gene says, suspicion definitely coloring his tone. "But you also said we were going to your place." You can see the wheels turning in his head and desperately search for something to derail his thought process.
"I didn't-" you start, but already realization is dawning in Gene's eyes.
"You came here out of reflex," he says, thinking out loud. "And it wasn't just reflex of visiting me - you genuinely thought you were driving back to your own dorm. But that must mean..." He looks at you sharply. "You already used the flashlight. You were a guy who used to live here."
"What?" you say, trying to sound surprised and confused. "How could I be a guy? I'm Lizzy. You know me."