This is from the fourteen mindfulness trainings from Thich Nhat Hanh, also called Thay. You can see them and more related information on the Deer Park Monastery website.
http://www.deerparkmonastery.org/mindfulness-practice/the-fourteen-mindfulness-trainings or here: http://www.mindfulnessbell.org/14trainings.htm
The Fourteenth Mindfulness Training: Right Conduct (for lay members)
Aware that sexual relations motivated by craving cannot dissipate the feeling of loneliness, but will create more suffering, frustration and isolation, I am determined not to engage in sexual relations without mutual understanding, love and a long-term commitment. In sexual relations, I must be aware of future suffering that may be caused. I know that to preserve the happiness of myself and others, I must respect the rights and commitments of myself and others. I will do everything in my power to protect children from sexual abuse and to protect couples and families from being broken by sexual misconduct. I will treat my body with respect and preserve my vital energies (sexual, breath, spirit) for the realization of my bodhisattva ideal. I will be fully aware of the responsibility for bringing new lives in the world, and will meditate on the world into which we are bringing new beings.
