The electron does not spend time because it does not move in the classical sense. You should simply think of a single electron as a fuzzy cloud and be satisfied with that mainly. It has a probability of being in a certain volume of space, which means it has a probability density at a point in space. The probability does not change with time. It does however oscillate at a characteristic frequency so that there is a phase difference between its conjugate properties. Therefore are the spatial volume becomes more defined as in parts of an orbital, the momentum of the electron within that area correspondingly becomes less defined. The electron also has quantum behaviour in that it may be in several places at once, by a process called "exchange". Such behaviour is called "delocalisation". This means that the energy of a chemical bond is not just the net electrostatic effect of the nucleus pulling on the electron "cloud", there is this "exchange energy" which is purely quantum mechanical. Also don't forget that the lobes of an orbital may be outside of the center of a chemical bond, so that some of the effect of these anti-bonding contributions may be to pull the bond apart to some degree.