What happens when two nitrogen atoms share electrons?
Covalent bonding occurs.
The very definition of covalent bonding is the sharing of electrons between two centres. That is 2 electrons form a region of high electron density to which the positively charged nuclei are attracted, and which cancels out electrostatic repulsion between the nuclei so that a net attractive force results.
The isolated nitrogen ATOM has 5 valence electrons. When 2 such atoms bind 3 electrons from each centre overlap to form a region of high electron density between and around the nuclei, which we conceive as