From "Metronome"

Timed like clockwork but executed with naivety, Jin had grown used to the consistent interruption of Beatrice’s phone calls during their Tuesday sessions. He tolerated them because Mrs. Carter did, but he hated the string of minutes he had to sit alone in front of the piano, waiting to feel like a human being, again.
But one Tuesday in August, Jin found her on the couch when he arrived for Jake’s lesson.
Even though he’d never met her in person, he could tell who she was from the self-satisfied slump of her body against the couch, the entitled way she let her flip flops dangle from her feet.
This felt inexcusable. Not only was Jake unable to practice, too embarrassed to practice at a “speed for dummies” in front of his girlfriend, but she went out of her way to distract him. Parading back and forth from the couch to the kitchen in terry cloth shorts that seemed to somehow get shorter with every trip.
Most lessons, Mrs. Carter timed her reappearance with the end of the hour, eager to know what Jin thought about her son’s progress. That day, while Beatrice chased Jake up the stairs with an open can of soda, Jin told Mrs. Carter that Jake seemed “distracted”. He thought this would suffice- in Suwon, it certainly would have, but Mrs. Carter only smiled, catering to his disappointment with a well-worn commentary about how very fast her little boy had grown up.
Jin got on a train that very same night for a meeting with a man he’d had sex with twice before. He didn’t know his real name, but his IM screen name was “BlowGo”. He had more hair on his chest than Jin would have liked, but he was ravenous and officious, insistent that Jin be in position when he arrived.
They’d prearranged a knock: two times, followed by a third, and Jin would move onto the bed and turn the lights off, and assume whatever posture BlowGo had specified in his text. When BlowGo fucked him, he did it fast and hard and it was over in ten minutes. Afterwards, Jin would curl up with his knees tucked into his chest while the hairy man cleaned up in the bathroom. They didn’t make eye contact and they didn’t say goodbye, and it was only from peering out the window that Jin realized BlowGo always paid the cab driver to stay.