I've gotten that question fairly often, along with the usual followup, "Does your wife know you're here?" I've always answered honestly, if for no other reason than I'm a basically honest person who doesn't seen a reason to lie when the truth serves or does no harm.
A) I've heard from a few dancers that singles tend to want more for less, while marrieds are more likely to not complain about reasonable prices. A group of circa five does not a statistical universe make, though.
B) In the long run, apparently not, according to those I've asked. Except for their strategy in how they then make the most money off the guy. :)
C) As I said, I always answer honestly. I don't see any reason to lie about it, and I've never had any any reason to suspect that a dancer failed to offer me a dance, or anything else, because of my answer.