Jerked off by your cute stepsister on vacation

I despise vacations especially when my go out to a nice dinner and leave me in the room with my step-brother. We were given explicit instructions to stay in the room until they returned. I'm sure! They're downstairs eating steak and lobster dinners and then will come back to take us out for burgers afterward. So unfair! And just because my step-brother and I aren't 21 yet, our think we're still to be on our own roaming the streets. My step-brother is 18 and I am almost 20. I think we are completely old enough to get out of this hotel on our own and explore. We are only staying here until the return tonight because they promised us extra souvenirs and cash to spend at the theme park tomorrow if we're on our best behavior tonight. Hmmm, so what can we do for the next 2 hours? I know! Lets do something that we wouldn't do at home. Lets make believe we're aren't related at all and we're stuck in this room together.