Are they always so damn slow to make official moves?
He may be making moves but they're sideways, like a crab. If you're enormously interested, you might want to invite him to dinner at your home. That's Cancer comfort zone. It means a lot to a Cancer, generally speaking.
Cancer and Pisces men like people to figure out their motives. Mind readers, in other words. Some people like the challenge posed by this. Others, who like forwardness, get exasperated.
Alot of their changeability is due to the Moon rulership - as it passes through each sign day by day it affects the state of being considerably. I've seen a Cancer Moon person morph and change like this quite dramatically. I have Mars and Saturn in Cancer, I do often forget to note where the Moon is and reflect on how I'm feeling.