Final answer:
Sexual arousal involves consensual psychological and physiological stimulation, starting with the excitement phase characterized by physiological changes, and non-consensual touching is considered sexual harassment.
Step-by-step explanation:
The subject of sexual arousal encompasses both psychological and physiological aspects that are part of human sexual response. When considering sexual arousal, it's important to recognize the critical role of consent and mutual participation. Touching another person's body without their knowledge does not result in sexual arousal; it is an invasion of their personal space and can be classified as sexual harassment. Moreover, sexual response during intercourse involves multiple phases beginning with excitement and extending through plateau, orgasm, and resolution phases. Kinsey's research and the studies by Masters and Johnson established the complexity of sexual responses and the nature of sexual health and behaviors.
In terms of sexual arousal, the initial phase known as 'excitement' involves physiological changes such as vasodilation leading to vasocongestion. This, in turn, causes the engorgement of blood in the erectile tissues in both men and women which results in enlarged genitalia and increased vaginal lubrication to facilitate intercourse. These responses are not elicited by non-consensual contact but through mutual and consensual stimulation.