"laws of (human) attraction"?

my husband & I are very content together. Couldn't be happier. If someone tries to show their interest in one of us - we brush it off as a complement as we aren't interested. A guy I deal with at work via phone & deliveries tried to show his interest. I happily mentioned about my husband to let this guy know that Im not interested or available. He was disappointed & felt a little sheepish for trying his luck. Weeks have gone by where hes been acting normal. But lately I have caught myself giggling & twirling my hair while talking to him. There is chemistry there - in all honesty. Im not going to deny it. But there is no way that I am going to jeopardise my marriage. We have worked too hard to get where we are today & are still very smitten of each other. The attraction between this guy & I is starting to concern me & I wish it would just go away - but it isn't. Has anyone got any tips of 'killing the romance'. I was considering telling my husband but nothing has happened & Im hoping in time things will dye down. I can't talk to anyone about it because they know how good my hubby & I are together & I don't think they would be too happy to hear what I have to say. I can't talk to him unless he tells me he is interested. It feels good to be wanted but guy is enough for me. Tips on how to make these feelings go away will be great!!