All Night in White Stains by Aleister Crowley.

“All night no change, no whisper. Scarce a breath
But lips closed hard upon the cup of death
To drain its sweetest poison. Scarce a sigh
Beats the dead hours out; scarce a melody
Of measured pulses quickened with the blood
Of that desire which pours its deadly flood
Through soul and shaken body; scarce a thought
But sense through spirit most divinely wrought
To perfect feeling; only through the lips
Electric ardour kindles, flashes, slips
Through all the circle to her lips again
And thence, unwavering, flies to mine, to drain
All pleasure in one draught.” [via]