The energy that we utilize and that is generated while having sex also gets transferred to the other person. Now whatever state that we are in, be it happy, sad, negative, depressed, frustrated, bliss etc. our energy is also of the same state and while doing sex we transfer the same energy and same emotions to the other person and absorb what the other partner has to offer. Now just imagine if we are in a happy and blissful state and the other person is in depressed or a negative state what will be the impact on our energy levels.