For some people, receiving fluids by vein and allowing the intestinal system to rest will be enough to treat the problem.
You'll need to conduct a few experiments to figure out what he means with a cheek kiss.
Maybe he just gives you the one raised eyebrow when he sees you, and you start to feel bad because you think this means he does not like you because you think that both eyebrows need to be raised.
It sounds like he likes you, but he is not in any place to follow through on those feelings without being immoral and causing a lot of stress for everyone involved.