One bed for two: testing family relationships on vacation

Vacation is always cool! Even if you have to go on vacation with your stepsister instead of a sexy whore you can fuck at any time of the day or night. But what can you do if your parents gave you money for a vacation with your sister and didn't give you any cash for hookers? And that would be fine, but there's only one bed in the hotel for the two of you, so you have to sleep with your sister. Anyone in this guy's place would have done the same, so don't piss on him... I mean, don't judge him.