Most men think of vaginal wetness as the most reliable indicator of a woman’s level of arousal; and while there is indeed a strong correlation between lubrication and sexual response, she may or may not be wet for reasons that have nothing to do with her level of sexual excitement. Breathing, on the other hand, is an oft-neglected indicator. As she gets more aroused, look for the commensurate changes in her breathing, and tightening of the abdominal muscles.