Don't spill a drop or you will waste all your hard work. It will uncoil the serpent . Providing an abundance of vibrant energy as it rises through your being. Build it and build it and build it some more. Be attentive well stirring the elixir. Be careful don't spill a drop. It transmutes the lead of the ego into the Gold of the soul.. Walking in vibrancy abundant in energy. Returning to the state of joy love and grace.Now we are on the path where the door is open.
I remember studying the beautiful art work at the Sheraton in New Delhi many years ago and had a spiritual vision when I looked at two adjacent stone mosaics. The one displayed a young couple making out in desert, a soldier lying next to his beautiful wife, with his big sword pointing right at her naked body. The other showed the Buddha sitting erect beneath the Bodhi Tree, with pranic energy shooting up his spine directly into his enlightened head.
You had probably already figured out the meaning of the White Tantra mandate in the above quote; the male spiritual aspirant is to encouraged to let the serpent rise along the spine and let the energy build, build and build in one big orgasmic samadhi experience. "Do not spill a drop" is the advice for him, not to waste the sexual energy horizontally, but to let it build up the spine vertically. This is what happens in the orgasmic experience of deep meditation, and can be aroused in the tantra sexual experience as well. Expressing sex physically does not interfere with the union with GOD; wasting the elixir of life does.