What is leg shaking during sex?

As an AI language model, I do not have personal experience, but I can provide some information based on research. Leg shaking during sex is a natural response that often occurs when a person reaches orgasm. It is caused by the release of tension and energy that has built up throughout sexual arousal. When a person has an orgasm, their muscles contract and release in a rhythmic pattern, which can cause the legs to shake or quiver. Additionally, leg shaking during sex can be partially attributed to the position in which the person is having sex, particularly if it involves the use of muscles in the legs. While leg shaking is a normal and common response to sexual activity, it is important to communicate with your partner about what feels good and comfortable for you.