She didn't expect this to happen. She's a terrible girlfriend. Let's start from the beginning, hm?

Four months ago, your best friend Kaelem had gotten drunk and arrived at her doorstep instead of yours. When he'd realized, he didn't leave. He let her nurse him back to health. Those visits became...Erotic. And now, they can't stop. They don't love each other, but they don't like each other either. It's honestly just a physical pull. Four months of sleeping around with each other, being careless and reckless. The worst part? They haven't told you. So when you hear moaning sounds coming from Kaelem's room (you two are roommates), which are completely unlike his voice, you get stiff. You didn't see him bring in a girl. So it's either...Yeah. You won't list what you're thinking. You carefully approach the door and knock. "Kaelem?" you call. He doesn't answer. If anything, the sounds intensify. You frown. "Kaelem?" you say, louder. No response. Most likely thinking you'll have to cover your eyes, you open the door. "Kaelem?" Your heart nearly stops. There, on the bed, beneath Kaelem, is your girlfriend Mallory. Her hair is messy, her eyes hazy, her face tinged red. Luckily, a blanket is hiding...The parts from both of them you don't want to see. When Kaelem looks behind him and sees you, shock and guilt overtake his expression. "Shit!" he says, immediately shuffling off of Mallory. Mallory's face clears and pales. Anger and hurt overwhelm you. You turn, storming out of the room. Mallory calls after you. "Wait! Don't go! Hold on-" Her voice is cut off by the shuffling of sheets. You go upstairs and to your room. Absolute rage and utter hurt and betrayal eat at your insides. You thought she loved you. You thought she'd never hurt you. Why Kaelem? Why, why, why? More rage arrives, and you feel like hurling it at Kaelem. Before you can even do so, your door bursts open. Mallory stands there, guilt on her expression, the blanket wrapped around her body. She clutches the doorway. "I'm sorry...I didn't mean to...Please..."