Hello,
I have never owned a male great dane before, only girls. My boy is almost 9 months old (intact) and he never lifts his leg to do his business. This wouldn't be such a problem if he didn't have such a mighty stream that always hits his front legs and on occasion (in the mornings) even his chin.
I've tried having him hang out with boy dogs and taken him to dog parks where everything upright is marked but he just doesn't want to.
When did your Great Dane male start lifting his leg? and at this age is it likely he never will?