I don't think I'd go, honestly. And I remember you had another thread where you said you were worried about your reputation with guys. This might make that worse if he is expecting sex and you take the trip with no intention of complying.
I would not go. Since he's single and just an acquaintance he might be expecting something now or later. Plus, if you run in similar circles your reputation could be questioned. You don't want anyone to think you can be "bought" so to speak even it seems like an innocous situation. For your personal safety as other posters have mentioned that is foremost, but there could be other negative consequences that are not so immediate.
hmmmm, unless he is gay, he is definitely going to expect s*x.
Just cause he expects it doesn't mean he's going to get it! Nor should you feel obligated.