Geldings will do that. So long as that can't do "THAT" well.... thank goodness for the old snipper-roo. :-) We had a gelding that would act VERY studly with "HIS" mare. We housed him in a paddock with a mare and he would charge the fence whenever anyone came near them. Needless to say that tryst ended right quick.
My first horse would actually "mount up" and go to town! I was shocked to death the first time I saw him do it. He didn't exhibit any other stallion-like behavior, so I don't know if he was "proud cut" or not, but needless to say, all the mares at the boarding stable where I kept him thought he was "The Man". ;o)