Give them something they really want.

"Wait!" Beth blurted. "You got me. I didn't really come here just to hang out. The truth is... the truth is that I need your help getting back at my sisters. They are always teasing me and making me distract random creeps while they go on super cool heists. I want you guys to screw them silly and put their pictures on that wall of yours to take them down a peg."

Yikes. Where had that come from? In any case it had worked. The prospect of claiming the three other sisters had drawn the bros undivided attention.

"I know them better than anyone. I'll tell you exactly what to do. You just have to bring the dicks."

Beth felt herself blushing. It was all just a ruse to buy her sisters time, of course... but she found the idea weirdly appealing. And besides, the DKM marked girls generally looked pretty happy. Maybe a little excitement would be good for her sisters?