Chemistry question on covalent bonds.?

my chemistry book says that in a covalent bonds if the nuclei move closer,the repulsion forces which are the nuclei of one atom repeling the nuclei of another atom and the electrons of that same atom repeling the electrons of the other atom,will increase and exceed the attractive forces.does this mean the repulsion forces will cause the atoms to seperate causeing thebond to break? also give me a answer to do not tell me to look it up