male/cub
If meaning an adult male on a cub, use instead: Older_male, adult_on_young, young_<form> (young_anthro/young_feral/young_humanoid/young_taur), younger_form.
If meaning a male cub, use instead: Young_male, young_<form>.
If meaning a male (in general) on a cub, use instead: Male, young_form.