Accuse her of cheating

"You cheated!" You shout, thinking of no better way to bring it up.

Olivia gives you an unconvincing shocked look.

"What? I would never." She pleads, barely being able to hold back a smile.

"That was clearly a fake orgasm." You say, looking back at Vivien. "Trust me."

"Really?" Vivien says as she looks from you to Olivia and back to you. "That means I'd have to trust that you actually know what her orgasms sound like."

Her cold words hit you hard as you hear laughter coming from Olivia.

"Sorry, maybe that was a little too mean." Vivien says, lightly stroking your face. "But cheating is a serious accusation, I'd hate to believe I couldn't trust one of you." Her tone is still sweet but you can hear a difference as a seriousness echoes behind it. "The question is, which one of you is untrustworthy?"