I had a female that did that, found her last male (of about 5 she ate) half way down her gullet.
Cuban females seem to need and only tolerate very macho and large males.
Had success with this pair
even at his size, she ruled the tank
She is beautiful... I wish I still have my female. She was paired with a Texas and NO I wasn't trying to breed them but they paired up doing that time while other cichlids was in my 125gl. She started pushing the Texas around and one night he just couldn't take it anymore and killed her.