hmmm. interesting topic, mostly because I know a few people that have been affected and it's been detrimental to their relationships.

Overly horny, insatiable sexual appetite, masterbation, porn, etc might not be sexual addiction by any means.

However, as with any "addiction"... often defined as obsession, compulsion, or excessive physical dependence
if it interferes with the functions of their life (work, family responsibilities, etc) or the relationships within their lives (spouse, girl/boyfriend, etc) I do think it's an addiction.

when self-control is lost, regardless of the consequences, it becomes an addiction imo.