I have a 5 year old neutered male- he was neutered at 6 months- fine.
2 years ago he suddenly decided that if any of my girls were in call the only gentlemanly thing to do was to oblige them
He grabs them by the scruff and gets his leg over- then he usually gets a thump for his pains
My neutered ex-stud cat never took any interest in the girls once he'd been done- no accounting for taste