Sacred Love - because it is sacred
Love is subtle; love is also supposed to be secret, because it is sacred. Love between two people or between God and His bhakta (devotee) is a sacred thing, not to be worn on one's sleeve, not to be ecstatic about in public, not to be exposed in Trafalgar Square or in Piccadilly. It is like the undercurrent in a river.
Taken from the book "HeartSpeak 2005", Chapter "Resonating With the Divine Being", pg. 140, by Revered Chariji