Definition - What does Horn Dog mean?
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.
Kinkly explains 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.