makes two sounds, "lubb" when the valves between the atria and ventricles close, and "dupp" when the valves between the ventricles and the major arteries close
The second sound of the heartbeat is called DUBB (S2) where the blood turbulence associated with the closer of semilunar valves at the begining of ventricular diastole
It is perfectly normal. There are plenty of other people out here with this fetish, however it is not quite as mainstream as some of the other fetishes. Check out heartbeatpleasure.net to see more...