For a while, I don’t hear Maria’s voice at all. I don’t hear the music either. The only sound in the yoga studio is Sandra’s lips on mine. Then the shuffle of clothing as it comes off. Then the heat of breathy moans. Then the swish of wet pussies. Then the slapping of skin as I finger her. Then the muted shrieks of orgasm. “Her turn,” says Maria, finally. I look up at her from my belly as I take my mouth away from Sandra’...