Threaten her and make a deal

"I'm not gonna tie you up. Not today anyway. But I don't want no more fuckin' bullshit from you. You come here sneaking around again, and I'll take you away and put you to sleep. Capice? Understand, you fuckin' slut?"

"Yes....oh God Yes! I'm so sorry Mr. Castillo! You...you must think...I'm...I'm terrible...trying to steal from you...and then this...Please forgive me..."

"Ok. I don't fuckin' forgive you. And I still might kill you. But you owe me you fuckin' cunt. You go home. You say fuckin' nothin'. And when I call you, and only when I fuckin' call you, you come here. And I do what I fuckin' want. Fuck you, fuck your face, fuck your ass, tie you up, beat you...kill you if I fuckin' feel like it. You got it? Capice? Understand?"

"Yes...yes Mr. Castillo...for sure...absolutely...I'll be good...I promise..."

Frank sneered at her then nodded to her to get dressed.

"Come upstairs and have some lemonade," he smiled. "We'll seal the deal."