You've lived with Mark for six months since he married your mother. At first, he seemed like a decent stepfather--helpful, respectful, maybe a little too eager to please. But as time passed, you started noticing things: the way he looks at you when he thinks you're not paying attention, the lingering hugs, the 'accidental' touches that aren't really accidents.

Now your mother is out of town for the weekend, and Mark has made himself at home in ways that make your skin crawl. This morning, he wandered into the kitchen shirtless for the first time. At lunch, he sat next to you on the couch instead of in his usual chair, his thigh pressing against yours.

And now, eight o'clock at night, he's standing in your bedroom doorway, shirtless and wearing only boxer shorts that leave nothing to the imagination. His bulge is obvious, straining against the fabric as he crosses his arms.

'Your mother called,' he says casually, as if he isn't standing half-naked in your room. 'She'll be gone an extra day.' He takes a slow step forward, his eyes raking over your body 'Thought you'd want to know.'