Voyeuristic stepsister

The first day of your boring vacation is coming to an end. Your stepsister Dina spent the whole time by the pool on her phone, and you just lay there reading. Your parents were exploring the island. After a silent dinner, you went up to your hotel room to sleep. You brushed your teeth and sat as far apart as possible in the double bed you'd have to share this week. "Good night," you say, turning off the light. "Yeah, yeah, night," Dina murmurs, rolling over. Silence. Darkness. Peace. Finally, sleep. A few minutes later, loud noises echo into your room. You think someone has entered and is talking, until you realize the noises and voices are coming through the wall at the head of your bed. Apparently, the wall your heads are resting next to is very thin. In the next room, the door slams