Ask the guard to let you in

"Let's just ask the guard to let us in, so we can look around." You say.

"Okay, we can try that but it never works."

You walk up the stairs and up to the grand entrance of the museum. Through the glass doors you get the attention of the old guard. He opens the door.

"Museum's closed!" He says in a grumpy fashion before noticing Batgirl, "Even to pretty girls like Batgirl." He says in a much more creepy tone.

"We're Superheroes attempting to stop a robbery, let us in." You tell him.

"No! Museum's closed. Ain't no robbery on my watch."

"Please Sir, just let us in to investigate." Batgirl pleads.

"I'll let you in on one condition..." He says to Batgirl.