This is my dream vacation.

Please communicate that to him, especially the fact that while you're feeling a little insecure, you trust him completely (unless of course, you don't, but that's a whole other comment). Feel your feels and keep checking in with him. It'll be clear pretty quickly if he's willing to reassure you or if he gets defensive and refuses. Then you have to decide what comes next.

This is kinda biased; lots of people are attracted to more than 1 sex so are they not supposed to have any friends while in a relationship like this?

That's why you do this... a test period to see if you're long haul compatible vs. lüst.

He might have actually been innocent. For now...

Hate to be that person but therapy (on your own first) would help you figure out if you want to stay.

Drop the class... go have fun.

Then I suppose, you don't love her enough.... not truly and not deeply. Simple as that.