If it is neutral then you are relaxed and offer no threat. The sexual response appears to be opposite to what common sense would dictate. Sexual arousal is a relaxation response. Anxiety often interferes with arousal, preventing it or diminishing its effects. Since the effects of the ANS are determined not by absolute activation but by balance and change, it is possible for sexual arousal to take place whenever there is an increase in parasympathetic activity compared to its former level.
Sexual orgasm is controlled primarily by the sympathetic division.
Orgasm can be accompanied by a sudden rush of blood to the internal organs, chilling of the skin dilation of the bronchi, producing a sudden, gasping intake or air a refractory period during which most internal stimuli are ignored and further arousal is difficult. This latter is due to the persistent circulation of adrenaline in the bloodstream. The psychological response to changes in the state of the ANS are in part a result of personal experience and learning. For some individuals, sympathetic activation for any reason can be intensely pleasurable. For others, it can be the basis for extreme fear.