To me partner is such a bland word, more like a cop out, with so many meanings. So is it your business partner, tennis partner, golf partner, dance partner, partner in crime, cards partner etc etc?. It gets extremely hard on the internet where you don't see the posting the comment who they are actually talking about. "I booked a flight for my partner".
As I said I must be old fashioned as I can never use the word partner to describe a the other person in the relationship. It will always be girlfriend, fiance, wife, spouse for me.