I suppose it depends on your definition but you start calling it as an addiction, treating it as a problem, when it interferes with your life.

By all means, have all the sex you want in whatever variety you want, but it’s an addiction, a problem, when you decide it to the detriment of something else. It’s a problem if it interferes with work or home life or social life or hobbies, or if it causes harm to yourself or others.