I don't think this is NSFW.
Perhaps he was used to getting no reaction whatsoever from his mating partners.
I guess you don't have to be too smart when you're the size of a moose. I got very close to a couple of them (not by choice) during the summer I spent working in Yellowstone Park. They are huge. Huge and grumpy. That's a bad combination.
List Of The Day: Stupid Animal Of The Day