Our step sister, Lily, had always been a tease. She'd walk around the house in her underwear, knowing full well how arousing it was for her stepbrother, Mark. One day, when their parents were out, Lily approached Mark with a naughty proposal. She wanted to watch him jerk off and promised to give him a reward if he finished on her panties.
Mark couldn't believe his ears. Lily, who he'd always fantasized about, was willing to let him cum inside her panties? He eagerly agreed, not realizing the extent of his desire for her until he saw her standing there, glistening with anticipation.
As he began to stroke his cock, Lily gently pulled down her panties and placed it on the ground between them. She teased him further by lightly running her fingers over his throbbing shaft until he could no longer bear it.
