Here’s the translation:

"The choice is yours. Or would you prefer me to play around with Caleya instead?"

"Don't touch my sister," Camellia said with emphasis.

The impudent man in front of her only laughed dismissively. "What’s the guarantee?"

Immediately, Camellia thought hard, struggling to keep her tears from falling. "I will do whatever you want. I will become your mistress."

And now, just look at how that bastard Luke is laughing with satisfaction.

Initially, Camellia was forced to become a mistress, but after someone from the past appeared, she now eagerly desires the position of a 'mistress'.

Luke wants Camellia to be his mistress because of her connection to the accident perpetrator.