I think a lot of people have experienced this. I enjoy going to my studio and I enjoy the people that are there. But it is definitely a business. They embrace (Literally) you when you walk in, when you walk out, and it's a very friendly atmosphere with flirting going on all over the place. My instructor is an intelligent beautiful younger woman and of course she just has that look that screams "come to me". Let's be honest....most dance instructors are attractive people....
They flirt (for the most part) in order to keep the students coming back. Let's face it, if you weren't having fun at the studio, most would stop going. Left foot here, right foot there is not fun...it's the personal interaction with the other people that keeps us coming back. A real simple way to figure out if there are feeling between you and your instructor is finding out how he interacts with you outside of the studio away from a studio event. Does he call you on his personal phone to say hello or does he call you only from the studio?
When I leave my studio, I do not hear much from my instructor until my next lesson. I'm OK with that as well, but that solidifies the belief that the flirting is purely for business purposes. Also, perhaps you can hang out at the studio and watch your instructor interact with other students. Does he flirt with them also? If he does, then it's all part of keeping the money flowing through the studio.
My point is, if the instructor is not making contact outside of the studio, then he is probably not interested and his actions are likely just to keep you coming back.
Just my two cents.