You never know. This could eventually turn into a physical affair or it already has and you don't know it. Emotional affairs count as cheating too and if he's done this for six months and you know about it the writing is on the wall. Move on.
Why are you putting up with it? Emotional betrayals are more deeply rooted than physical ones. So I ask you, if your hubs is finding his emotional needs met by another woman, what are you sticking around for?!
It all depends on your and his relation first. If it has flaws, then your losing time. If you 2 are happy then all other things are just affairs. Cheers.