Sirius took Beth's hand as they left the Common Room. "What's on the agenda for today, teacher?" he asked her.

"We're going to work on getting you to turn your head to the side when you breathe during crawl stroke," Beth replied.

"Where the fuck do you think I turn my head?" Sirius asked belligerently.

"You turn it quite a bit further than you need to. It slows down your timing and you'll eventually hurt your neck when you're swimming longer distances," Beth said. She braced herself for his response knowing from experience he'd be annoyed. Sirius was a natural athlete and he was used to doing well at everything he did. He was frustrated he hadn't progressed faster not realizing how quickly he was learning.

"Bloody hell," Sirius fumed. "I don't know how you expect me to not swallow water if I barely turn my head."

"It just takes practice," Beth reminded him, trying not to laugh. "You've come a long way since we started."

Sirius didn't respond but Beth eyed him furtively and could see he was mollified. They chatted easily as they descended the marble staircase and turned towards the back door. Lily and James waved them down before they left the Great Hall.

"Lesson time?" James asked. Sirius nodded.

"How are Sirius' swimming lessons going, Beth?" Lily asked.

"Really well. He's shown a lot of improvement." Beth slipped an arm around Sirius' waist and grinned at him. "Although I'm mauled more in our lessons than I was playing water polo."

"Sometimes I get a little nervous that I'll sink," Sirius told her with a straight face. "I have to grab on to you to stay afloat."

Beth rolled her eyes. "Most of the time you grab me when we're standing in the shallow end of the pond."

Sirius just grinned at her. "You know I wouldn't even bother taking these lessons if you weren't teaching them, right?"

"These lessons are important," Beth lectured him. "Someday you may need to swim a long distance. You'll use less energy to swim and be able to go a lot further the better the swimmer you are."

"Yes ma'am," Sirius said mockingly.

James shook his head. "You have our sympathy, Beth, for putting up with him." Sirius gave James a playful shove that landed James against the wall a few feet behind him and then ushered Beth out the door quickly before James could retaliate.

"I'll catch up with you later, Padfoot," James called, a promise in his voice as the door swung shut behind them.

The lesson went by quickly. Sirius made progress on his side breathing and swam slow laps while Beth completed her work out. During their play time towards the end Beth showed him ways that water polo players stopped other players from moving underwater. "These moves are against the rules," Beth explained. "But the refs can only see so much from the deck of the pool and everyone does them. That's why girls wear high-necked swimsuits that are super tight. It gives opponents less to grip."

"Is there any co-ed water polo?" Sirius practically leered. He looked forward to this part of their lessons and learning water polo moves was no exception.

"No, for good reason," Beth laughed. "But sometimes we practiced with guys for fun."

The thought of other blokes groping at Beth in the pool shook Sirius. He knew now how physical water polo was. He frowned, feeling a stab of jealousy. Beth read his expression and slung her arms around his neck. "Hey, that's in the past. I'm here now."

Sirius hauled her closer to him. His lips met hers and for several seconds he was able to tread enough with his legs to keep his head above the water. That didn't last, and they broke apart laughing when they had sunk so much that the water was up past their mouths.

They swam to shallower water and Sirius launched himself at Beth. He pulled her up against him in the waist-high water, the inside of his hot mouth contrasting with the cool water droplets on their lips. Beth used the water's buoyancy to crawl up his body and wrapped herself tightly around him. The air was chilly but where their bodies clung together was heated. Sirius' hands moved down her back, his hands warm on her exposed skin. "Shit, Beth," he murmured, his lips moving hungrily against hers. Beth squirmed against him and her hands had slid up to the nape of his neck to press him closer when they heard voices coming towards them. Sirius fell backwards as their lips broke apart and they splashed into the water, giving them time to come up a few feet apart from each other.

Whoever the voices belonged to turned a different direction to walk past the pond. Beth and Sirius grinned conspiratorially at each other as they left the pond, hurrying to their towels and clothes.

"Another invigorating lesson," Sirius said casually.

Beth wasn't duped by his tone. She smiled as she slipped her feet into sandals. Sirius grabbed their bags and they walked towards the castle. He put his arm around her and kissed the top of her head, looking down at her with a gleam in his eye. "Seriously, babe, thanks for putting up with me. I know I'm not the easiest git to teach."

Beth shook her head. "You're actually much easier to teach than you realize. I've taught kids to swim before and they aren't anywhere near as coordinated or as strong as you are. You're becoming a good swimmer quickly."

"Flattery will get you-"

"Posters of muggle girls in your room wasn't enough for you, was it Sirius?" A scornful voice spoke, interrupting Sirius. A dark-haired wizard approached them from the other side of the pond and they turned towards him in surprise, not having noticed him. "You just had to go get the real thing."

Beth recognized him as the Slytherin wizard she had seen at her first Quidditch practice. Sirius' arm had turned wooden and she felt tension radiating from him.

"Fuck off," Sirius' voice was cold, but Beth could sense a heated emotion under a thin veneer of indifference. Her head whipped between their expressions, Sirius' hard and the other wizard's derisive.

"Aren't you going to introduce me to your girlfriend, big brother?" The wizard sneered. Beth froze. Her eyes flicked to Sirius whose face had darkened. Brother? Sirius had a brother at Hogwarts and hadn't told her? "Mum would be mortified at your manners," the wizard continued. Beth's stomach sank as she now recognized this as the voice that had interrupted them kissing the first time in the corridor. She stared at the wizard with wide frightened eyes, her mind reeling with this new knowledge.

Sirius didn't speak, just glowered at his brother. "You just had to find the ultimate way to humiliate mum, didn't you?" the wizard continued caustically. Beth flinched drawing the wizard's attention to her. Sirius' arm tightened around her shoulders and Beth unconsciously clung closer to him. When Sirius did not respond, the wizard shot a final strange look at Beth and then walked away.

Sirius pulled Beth into the castle, moving so fast she stumbled to keep up with him. Once inside, he dragged her to one of the corridors on the first floor, deserted on a Saturday afternoon. He was breathing rapidly and he stopped and dropped his arm from around her shoulders, his other arm still automatically holding their bags.

The wizard's words reverberated in Beth's head. Her chest hurt as she struggled to calm her breathing. Sirius faced away from her, his shoulders heaving with fury.

She broke the silence first, her voice hoarse. "Your brother is here Hogwarts." Not a question, but the statement was filled with questions.

Sirius finally turned around. "Yes. That was my brother Regulus." He heard her unspoken questions, but hesitated, not knowing how to explain, still battling his own anger and fear at Regulus' words. "I told you, I'm estranged from my family. Reg and I normally try to avoid each other."

Beth waited but Sirius didn't say anything else. She needed more, but he stood there, jaw clenched, his face still stony, not speaking. She turned away in frustration and started walking down the corridor and Sirius fell in step next to her.

They walked several minutes without talking. At first Sirius was relieved Beth wasn't questioning him, but as the minutes passed he became worried. There was something ominous in her manner as he tried to figure out how to tell her about his fucked up family. Sirius didn't frighten easy, but this silent closed-off Beth scared him. She walked by his side, stoically staring straight ahead but he felt her retreating from him. He wasn't sure how to close the distance between them.

Sirius finally couldn't take it anymore. He grabbed her arm and pulled her to a bench set in an alcove. "It's not like that, Beth."

Beth's face was set. "Like what?"

"I'm not with you to piss off my family." Sirius tried to unclench his jaw.

"Are you sure? You never even mentioned your brother was here at Hogwarts." Beth replied. Her voice was shaky. Sirius could see the hurt blossoming in her eyes.

"It's not why you think," Sirius gulped. "I care about you. I don't care that you're not a witch, but my family would."

Beth looked away. Her shoulders slumped. "Then why?" Her voice sounded near tears. "Why didn't you tell me?"

"I told you I don't care what my family thinks," Sirius gritted his teeth. "I didn't mean to shut you out about my brother being here. We treat each other like strangers. He doesn't matter to me."

Beth stared at him. "He's your brother," she said, her voice shaky. "Even if you don't like each other, he'll always matter to you. Maybe not entirely in a good way, but in other ways. You should have told me about him."

Sirius drew a shaky breath. "You're right," he conceded finally. "I should have told you about him." He sat down next to her on the bench after dropping their bags on the floor, struggling to find the right words. "We were close once. He followed me around, looked up to me, normal brother stuff." His eyes were far away. "But I don't regret running away from home."

He looked at Beth and was relieved to see the shuttered look had left her face. Her eyes still looked wounded and he leaned towards her and cupped his hand around the back of her head. "I've tried to separate my family from my life here. I don't think about the way my brother and I used to be. He's a sodding stranger to me now." His hand moved down her hair. "It's easier that way. I'm sorry, I didn't think about how I was keeping you out."

Beth's mouth twisted. "You're sure there's not some part of you that is attracted to me because I am everything your family detests?"

"No!" He said it emphatically. "I don't normally have contact with muggles, just muggleborns. I always considered them the same as purebloods. It never crossed my mind to become involved with someone because of their blood, one way or the other."

"It doesn't bother you that I'm a muggle? That's even worse than a muggleborn. I can't do magic." Beth's shoulders slumped dejected. "You were right when you first met me. You said I'd never fit in."

"You fit in with me," Sirius protested. He gathered her into his arms and held her closely. "Look, I know we're always going to be different. But I'm happy I met you. I've never felt this way about anyone before."

Sirius cupped Beth's face with his hands so he could look into her eyes. "There's more to me than my ability to do magic, Beth. You challenge me, you understand me, you make me laugh, you put up with my shite." He ran his fingers through her hair. "I care about you, as a person. The fact that you can't wave a wand and do spells –that's far less important to me than you are."

"Except that I can't protect myself and you have to worry about me," Beth wiped her eyes. She looked vulnerable and sad, as if facing a truth she had tried to avoid.

Sirius dropped his hands and stared at her, trying to work out what to say. She was right but how could he explain to her that she was worth it? "That's true. We are facing issues we wouldn't if we were the same. But I'd rather face these issues with you than be without you without a care in the world."

"I'm making your estrangement with your family worse," Beth continued morosely. "I'm driving another wedge between you and your family."

"No, you're not." Sirius was becoming exasperated. "Look, my family and I are done. You can't make it worse, our estrangement is final. The issues between them and me are far bigger than you as a person. Don't you see that? Everything they stand for is repugnant to me." Beth's eyes were downcast, and he put a finger under her chin to lift her face. Her eyes when they met his were worried yet Sirius saw a glimmer of hope in them. "Beth, you mean so much to me," he said softening his voice. "I'm happier now being with you than I ever have been."

Beth's body sagged with relief. "Even when I'm being stubborn and insecure?"

"Even then," Sirius smiled.

Her lips curved as she looked up at him with shiny eyes. She flung her arms around him and hung on tightly. Sirius kissed her hair. "Don't ever doubt how much I care about you," he rumbled against her ear.

"I'd just like it better if you didn't hide important stuff from me," Beth said.

"I was stupid not to have told you about Reg. But I still might not tell you some things if I feel it would help protect you," Sirius admitted honestly.

"You're overprotective when it comes to me," Beth fretted. "That might make things more difficult for us."

"I know," Sirius ran his fingers down her back. "I can't help it, Beth. I never expected how strong my feelings could be. I'm doing the best I can."

Beth nodded. This relationship wouldn't be easy, but studying Sirius' anxious eyes watching her, she knew she was willing to fight for it. "Me too."