Vijnana Bhairava Tantra · Dharana 45 · Verse 68
Joy between start and end of union
During intimacy, rest attention on the joy that runs between the beginning and the end of the act: not on performance, not on finishing, and not on the other person as an object. The method is awareness of joy. If the mind turns the moment into a project, the practice has already been left behind. Stay with the current itself.
Older line
Cast a mind full of delight into the middle, between the fire and the poison, with the breath simply still or held full, and you are joined to the bliss of love.