"Isn't that your boyfriend?" Linda, the girl from my literature class, asks as we sit down to lunch. I glance to where she's pointing behind me, and see Derek sitting with Michael and Ryan on the other end of the dining hall.

I blush. It's been almost a month and I'm still not used to it. Derek is my boyfriend.

"Oh, um, yeah," I say, a small smile escaping.

Linda grins at me and rolls her eyes. "Wow, you've got it baaaad," she laughs. "Let's go sit with them."

"You don't mind?"

"Of course not! Maybe you can introduce me to those two guys he's with. Are they single?" She winks at me.

I glare at Michael from across the dining hall as we get up and walk towards them. "They are. But avoid the blonde. He's an asshole."

I'm not totally sure what happened between him and Sarah. Things seemed like they were going well, until about a week ago. She came home from his house crying, and from what I can tell, they haven't talked since then. She keeps saying it's no big deal, it just didn't work out, but she won't tell me details. I keep imagining all kinds of horrible scenarios.

"Hey!" Derek grins as he catches sight of me. "What are you doing here? I thought you had class?"

"We got out early!" I say happily, and sit next to him. He squeezes my hand in greeting. I know I'm grinning like an idiot but I can't get used to how happy he makes me.

It still feels weird and scary to be this open. I don't have to pretend he's not my favorite person anymore. We're together. We can sit next to, instead of across from each other. We can smile at each other. We can hold hands. We can even kiss if we want to.

We hang out and study everyday. We eat dinner together every night. We watch tv together, without even fighting about it. Sometimes I spend the night and I get to wake up, snuggled next to him.

I'm half braced for the other shoe to drop, but so far it hasn't. Everyday is like a high school daydream.

"Ryan, this is Linda," I say with a smile. I glare at Michael and pointedly don't introduce him.

He rolls his eyes. "I'm Michael," he says. "I recently got dumped by Casey's best friend and for some reason, Casey has decided to hate me for it."

I frown. I didn't know Sarah dumped him. I didn't even know they were together, in so many words. I thought they were still in the dancing around it stage. I guess, to be fair, most people don't spend years doing that.

Maybe I should back off a little on hating him. At least until I have all the facts.

"Oh," Linda says awkwardly. "I'm sorry to hear that. Umm… so you guys are all on the hockey team?"

It's not the smoothest conversation starter, but it does the trick, and everyone moves past the awkward moment as they talk about the upcoming game. It's one of the biggest games of the season, and Linda is apparently a hockey fan, because she jumps into the hockey talk with a lot more knowledge than I have.

While we're all talking, Derek gets a text message. I wouldn't have even noticed, except that he stiffens next to me as he reads it.

"What's wrong?" I ask.

"Nothing," he says quickly.

Something is really wrong. His jaw is clenched, and he kinda looks like he's going to be sick.

"It's not nothing" Michael says with a concerned frown. "You okay?"

"Yeah," Derek says. "Yeah, I'm great. I umm. It's good news actually. My Dad just texted me." He's very pointedly not looking at me. "Did you guys know they invited our families to come to the game? Since it falls during Family Day weekend?"

My breath catches and it feels like my heart is going a mile a minute.

"Yeah!" Michael says enthusiastically. "It's the one game my family comes to every year!"

"Right," Derek says. "My family is coming too."

"Your whole family?" I ask in a strangled voice. Where did all the air go?

"Yeah," Derek says. "Everyone."

Ohmygod.

The other shoe just dropped.

I somehow make it through lunch, although I think everyone knows something is wrong and they choose not to probe. It'd be hard not to notice, as I can't bring myself to touch, talk to, or even look at Derek for the rest of the meal.

I eat woodenly and bolt as soon as I possibly can without being totally rude to Linda.

I'm freaking out. I am 100% freaking out. I promised I wouldn't do this ever again, but I'm ignoring Derek's texts and phone calls. I just need a second to figure out what we're going to do. The family is coming here. What are we going to tell them?

I pace my room back and forth. Sarah is in class, and I couldn't talk to her anyway. She doesn't even know we're step siblings.

Oh god, if they come, everyone here will know. I'm not ready for that yet. We've been living in this amazing bubble where we can just be us. We're not step siblings. We're just two people. Casey and Derek.

It's not reality, I've always known that. It's a fantasy I created with a simple omission. I don't know how I let myself get lost in it.

"Casey!" Derek pounds on my dorm room door. "Let me in!"

Oh god. I'm not ready to talk to him. But I promised to never shut him out again. I pull open the door, reluctantly.

He bursts into the room and slams the door behind him. "Geez Casey," he says. "I knew you were going to freak out. I shouldn't have told you at lunch. But I hoped…" he trails off. "I didn't think you'd freak out this badly."

"You're freaking out too!" I accuse. I glare at him. How dare he act like I'm overreacting.

"No I'm not," he says, voice deliberately calm. "And I don't know why you are. Did you think we would just not see them ever again? I knew this was coming eventually!"

"Of course I knew that too!" I snap.

But it wasn't supposed to be until summer. Derek has to stay through spring break for hockey, and I was going to pretend I had too much studying to do to go home.

I had a semi plan. A plan to wait and see how things were going, after a whole semester of dating. I thought by then, we'd know what to do.

It wasn't supposed to happen after just a few weeks. It hasn't even been a full month. It's still so new.

Obviously, we can't tell them anything yet. Which means we'll have to pretend to be like before.

"Our dynamic now is so different from high school. I don't know how we're going to pull this off." We're nothing like we were in high school. We haven't fought once since we got together. Derek hasn't even pranked me.

"Pull what off?"

"Acting like nothing has changed! Being like we were in high school. They're never going to buy it."

"That's your plan? To act like nothing has changed?" He looks at me like I just slapped him in the face but I don't know why.

"Do you have a better idea?" I ask angrily.

"Yes! How about we tell them the truth?"

I stare at him with my mouth open. "Because it'll go badly!" I finally burst out. Is he really this dense? "They're going to freak out."

"So what? You're planning to just never tell them? Just keep acting like step siblings that get on each other's nerves whenever we're around our family? The most important people to us? You're gonna lie to your mom and Lizzie and hide our relationship like it's some dirty secret?"

What is he even talking about? He's not a dirty secret. But we are step siblings. Why is he acting like it's not complicated?

"I'm not saying I'm never going to tell them. I just don't see why we would tell them now. If we tell them now and it doesn't work out, then we'll have opened that can of worms for nothing!"

I think maybe I shouldn't have said that out loud. He's giving me this stunned look and his face is pale and he's definitely taking it wrong.

"Derek-"

"So you're just waiting for this to end?" He cuts me off. "It's not real to you. You keep saying it doesn't feel real. What am I to you Casey? Just some guy that you get to switch on and off like a light? Away from home I'm your boyfriend, but around family I'm your step brother?"

"You are my step brother!" I yell. "Why are you trying to act like that doesn't matter? We've been playing house in this ridiculous fantasy world where no one knows about it. We keep pretending it doesn't matter, but it does!"

"It doesn't matter to me," he says flatly. "I didn't realize how much it matters to you. Being with you is my reality. You're my step sister and you're my girlfriend. I'm not pretending to have two separate lives. I thought I was giving you time to get used to it, but you're not going to, are you? What are we even doing Casey? Why are you with me?"

What is happening right now? How did this conversation spiral so badly out of control. "I'm with you because I like you," I say. "I like being with you."

He looks at me for a long moment, like he's searching for something. He shakes his head slowly. "I don't think that's enough," he says softly.

His face hardens. He's wearing this sneer I haven't seen in years. My heart sinks. "The good news is you don't have to worry about the family anymore."

"Why?" My voice is timid. I hurt. I hurt so badly and I know what's coming. I'm not even surprised when he says it.

"I'm breaking up with you."