In what way(s) does engaging in sexual activity affect meditation practice?

Question

Does sexual activity (masturbation and beyond) hinder vipassana meditation practice? If so, does anyone know through experience or references exactly how this activity affects the practice? For example, does it decrease one's ability to focus?

Answer 1

Sensual pleasure is one of the Five Hindrances which are like "canals dissipating the force [awareness/discernment strength] of a river current" as taught by the Buddha in AN 5.51:

"Sensual desire is an obstacle, a hindrance that overwhelms awareness and weakens discernment. Ill will... Sloth & drowsiness... Restlessness & anxiety... Uncertainty is an obstacle, a hindrance that overwhelms awareness and weakens discernment. These are the five obstacles, hindrances that overwhelm awareness and weaken discernment. And when a monk has not abandoned these five obstacles, hindrances that overwhelm awareness and weaken discernment, when he is without strength and weak in discernment: for him to understand what is for his own benefit, to understand what is for the benefit of others, to understand what is for the benefit of both, to realize a superior human state, a truly noble distinction in knowledge & vision: that is impossible."

"Suppose there were a river, flowing down from the mountains — going far, its current swift, carrying everything with it — and a man would open channels leading away from it on both sides, so that the current in the middle of the river would be dispersed, diffused, & dissipated; it wouldn't go far, its current wouldn't be swift, and it wouldn't carry everything with it. In the same way, when a monk has not abandoned these five obstacles, hindrances that overwhelm awareness and weaken discernment, when he is without strength and weak in discernment for him to understand what is for his own benefit, to understand what is for the benefit of others, to understand what is for the benefit of both, to realize a superior human state, a truly noble distinction in knowledge & vision: that is impossible."

Answer 2

In Vipassana you have to maintain equanimity without clinging and craving. When engaging in sexual activity you entertain clinging and craving. This your weakens your mindfulness and concentration hence your ability to see things as they really are.