It's usually fine to let "boy" and "girl" horses hang out together for da first nine months or so, but then it's best to separate da genders into different pastures before da colts start "getting any ideas" due to said afillyations.
Buford Tannem seemed to really relish dancing with Clara Clayton, but --- due to his being such a hostile jerk and his disparagingly referring to her as a juvenile female horse --- said pretty schoolteacher did not find said affillyation to be overly enjoyable herself.