Do it! Sex is fun and awesome, especially if he is paying for a nice hotel room. Just make sure you use a condom and don't catch feelings.
I hate how people are always like "you will regret it, wahhhh". It's the 21st century, we live within a hookup culture. If you want to have sex, go for it! If you don't, then don't. Feelings shouldn't even factor into this decision because it's supposed to be no strings attached.
It's simple, stop making it complicated.