I had the exact same thing! I, too, thought it was food poisoning, because me and my kick-ass immune system managed to beat it over one very long, very harrowing night of bad dreams and constant nausea and sleeping on the floor by the toilet.

The next day? I found out that my sister and my mother, whom I'd been hanging out with two days before, BOTH had it. And worse than I did. Your poor SO is in for a looong night, huh? :D