We know many people don't like to talk about the taboos of the boudoir, but your habit could be stifling things in the romance department. Some of the chemicals found in a cigarette can damage the blood vessels in a man's "nether regions" leading to erectile dysfunction (ED). In fact, research has shown that men who smoke have a 60% higher risk of ED than men who don't puff.
There is also a correlation between sexual performance and testosterone levels. Testosterone is the hormone that drives the libido in both men and women. When you smoke, you temporarily increase the level of carbon monoxide in your blood which over the long term reduces our ability to produce the hormone. So the lower your level of testosterone surging through your system, the lower your libido.
And if the goal of your bedroom romps is to have kids, you should definitely think twice about lighting up. Men who smoke have 23% less sperm on average and the remaining sperm have lower motility levels (meaning they are not great swimmers)!
Obviously the best thing to do to re-ignite the fire is to quit smoking.