You play along

You are not leaving Stacey here with this girl, who you now realize is a certifiable sociopath. You decide to play along for now, hoping to get your chance at swiping back the marker so that you can free your girlfriend and get **** on Olivia for what she was making you do. Or, that's what you try to tell yourself, not fully willing to admit that you also, kind of want to see Olivia cream into your girlfriend's pussy.

"P-please Olivia, can you cum in my girlfriend?" You utter in a defeated tone.

"Well, okay Finn. If you really want me to." Olivia responds as if she's doing you a favor before impaling your girlfriend on her long, rigid pole.

"Aaaaaaaaaaah! Thank you mistress!" Stacey cries, looking like a junkie who's finally scored her second hit.

"I finally get why boy's are so obsessed with their penis's. It feels so good to be the one fucking as opposed to the one getting fucked all the time. I might have to make this a regular thing, Monday night monster cock night!" Olivia laughs while bouncing against your girlfriend's body, cupping and squeezing her own breasts in unabashed glee.

"I-I'm sorry Finn! I just can't resist this cock. It feels too good!" Stacey's mind breaks down into her baser instincts and she starts bucking against Olivia without reservation.

Olivia notices your hand gripping the outside of your thigh. "Go on, you can jerk off if you want to." She offers and watches you closely, as if waiting to see if you'll rebel.