my cat is a dick

i dont know whats gotten into him lately. ever since Romeo died, (his buddy) hes been a super prick to my female cat. they are both fixed so i dont know what his deal is. plus its not like shes new. ive had her for a few years now and he never bothered her before. i definitely think it has something to do with the other cats death. is he mourning still? angry? loney? resent her? she didnt do it, but maybe he blames her? (romeo died of cancer). or maybe he just sees the lack of any other males around to mean hes top shit now, and hes just being all fucking macho.  hes such a HUGE cat, hes going to really hurt her one of these days. i dont want to rehome him. maybe if i got a new kitten it would settle him down? i dont really want a new kitten either. i got enough friggin animals. i dont know how to fix this