Boyd doesn't actually sing for anyone. It's not that he can't, or he's shy. He just likes hearing other people sing. Specifically, Erica. He specifically likes hearing Erica sing. But she likes hearing him sing, too.
The first time she heard him sing was the morning after she slept over at his apartment for the first time. He was in the shower and naturally, Erica had to sneak up on him, scare him so he'd fall on the floor naked and wet and she could laugh and have a reason to jump his bones at nine in the morning. But she didn't do that. She just stood outside of the door and listened to him sing "Drops of Jupiter". She sat down when he went into "Look What You've Done" because it reminded her of her older brother's love of Jet. It was more than impossible for her to hide her smile when he started on "A Drop in the Ocean" because she knew he was singing it about her. A boxer-brief clad, just rolled out of bed Isaac appeared in front of her. Boyd had only told her so much about his roommate the night before, and in other conversations they'd had while studying in Starbucks and hanging out on the green with her own roommate. "Who're you?" Apparently, he hadn't told his roommate about her.
Before she could respond, Boyd came out of the bathroom, a towel wrapped high enough that nothing was exposed, but low enough that it left little to the imagination. "I told you about Erica, man." Oh. So he did. Isaac scratched his head; he was obviously still clouded by the remnants of the sleep he'd been indulging in only minutes before. Boyd went back to his room and Erica followed behind, smiling. "You heard me, didn't you?" He sat on the bed so the most she saw of him was his ass as he put his boxers on, even though she's seen much more of him the night before.
"I didn't know you could sing." She folded her arms over her chest. The gesture pulled the shirt of his she was wearing up slightly enough that he could see she was definitely not wearing underwear. All he did was shrug and pull a very fitting V-neck over his head.
"Well. Now you do." His response was dry and it cracked through the air, surprising her. She went up to him, putting her hands on his covered chest and smiled.
"I like your singing."
The first time he heard her sing was the first time she cooked dinner after she moved into his apartment. Boyd was always very silent in his movements, whether he was in the apartment or not. He was coming in from his shift at the Starbucks they frequented (as much as he was sick of everything about the place), when she was making food for them. Isaac was out, had been out for the whole day, so it was just them. He closed the door behind him, but she didn't hear the click of the lock. She was too busy singing "I Could Fall in Love" because she was raised on Selena and Celia Cruz, Marc Anthony and Menudo. Her voice was soft, comparable to her fiery personality he loved and it took Boyd by complete surprise. She still hadn't noticed him standing at the entrance to the kitchenette, but he didn't want to disturb her even though he knew she was singing about him.
He went up behind her after a moment, wrapping his arms around her waist and kissing her neck. "I didn't know you could sing, either." He rested his chin on her shoulder and looked at her, smiling.
"Well. Now you do." She turned around and kissed him before going back to the food and humming the rest of the song.
He didn't say anything until that night, when her back was pressed against his chest and their legs became a tangled mess of appendages and his arms held her, protected her and hers held onto his, just for reassurance. "I like your singing, too."
They both sing for each other a lot, all the time, but not in front of other people. The singing all but ceases to exist whenever Isaac or his girlfriend is around, and it isn't even a thought when one of the parents comes to visit.
The only time she caught him singing to someone else was when their newborn daughter, Alexa, was practically inconsolable one night. They usually switched off during the night, so one would sleep and another would take care of whatever she needed. By that point she was sleeping for four hours at a time, but this night she wouldn't sleep for more than twenty minutes. Erica was distraught, near tears, though she hated having anyone see her cry, but Boyd assured her he could handle it. In one swift, connected movement Boyd had gotten out of bed, got his daughter in his arms and was out of the room, leaving Erica with a quiet she hadn't known in almost two days. It was eerie how quickly it got quiet, so she went to see what the hell he'd done that she didn't do.
She watched him walk around with the tiny, red-faced bundle and sing "Isn't She Lovely" to her. The baby didn't fuss, didn't even stir while he sang and she smiled to herself as she leaned against the wall. He sang the chorus over and over until she was asleep, and Erica walked over to him, putting her arms around him. "I don't think she knew you could sing."
He looked down at the baby, her brown skin contrasting slightly with the peach fuzz of blonde on her head. "Well. She does now."
They watched her sleep for a moment, making sure she wouldn't wake up for at least a half hour. Boyd took a seat on the couch and Erica sat next to him, resting her head on his shoulder. They both let out a small chuckle when the baby started to squirm, contorted her face before Boyd started to sing again and she relaxed, definitely asleep. "I think she likes your singing."