A horn dog refers to someone, usually
male, who is often horny. This person acts like they are always
in heat, constantly looking for someone to hook up with. When a
prospective partner isn't within sight, they take it upon themselves
to relieve their horniness.
More About Horn Dog
There is nothing wrong with being a
horn dog. It could be a phase, as with teenage boys. So, one should
enjoy it while they can, but keep in mind that it is not okay to push sexual advances on people who say no or otherwise show you that they are not interested. This frame of mind can also be a physical or psychological
predisposition. As long as sex is consensual and safe, one's free to
act upon their horniness. It only becomes a problem when being a horn
dog results in abusive behavior.