They are related to our own bed, in that we come from the parents bed, and their lives are therefore intrinsic to our own in a retro way. So we donate to them. We donate to Gurudev, and his temple, so we donate to the twelfth house. God requires the essence of our lives, which is our love. The twelfth house is this outflow direction of energy.
Energy is lost in sex, exchanged, enjoyed, given off, but enjoyed.
Similarly donations to proper lineages of faith, or the pure twelfth house, also feel good, in that when one gives to one's conception of God, one gets relief from their fears of God. The relationship becomes sweeter rather than distant. So it is with lovemaking, and so it is with God. It is the deepest satisfaction for the heart of the Vedic father if the child understands and heartily accepts these Spiritual principles from early in life and continues on this wholesome path. If it be pure, then the fathers heart will be pure, and the childs future will be pure, and the child will give rightly, to the properties of God on Earth.