I wonder...our dog here..(well, not mine, but my fiance's mother's), kinda does that too. She can't have water down 24/7, because, according to my fiance's mother, "She'll make herself sick with all the water she would drink". So when she's thirsty, she has to ask for it(by doing her doggie thing and spinning around in a circle and looking at me, and then her water bowl), and then she can only have half of a bowl. And she won't drink stale water(but that's probably her just being particular). But she doesn't act nearly as obsessed about it as your boyfriend's dog does. I'd agree, he probably does need to see a vet.