Susie replies:

An orgasm is an intense sensation that people feel when they are at the maximum height of sexual arousal, also known as climax. When people have sex, the sensations they feel follow a progression that goes: desire --> arousal --> plateau --> orgasm --> resolution. So basically, you start out wanting sex, like the idea comes to you or something. Then you get turned on, whether by foreplay or some other stimulation. Then your level of arousal goes up until it kind of levels off. Then at a certain point, the intensity spikes and you experience a big rush of blood, tensing of some muscles, hair standing on end, racing heart rate followed by a swift and intense feeling of release. After that, things cool off and you are done(unless you go again -- people with vaginas can have another go, whereas people with penises require some time to reload -- aka refractory period).

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