You must have being very pleased to see Leo return,..its a worry when they vanish like that as you imagine all kinds of reasons for not returning,..one of mine left home,.."Olivia",.. i found she decided to remain outside a neighbors back yard,.. for a year,..then no sign of her anywhere,..she turned up three months ago and only drops in for food once a week,..she was my indoor cat for years,..weird!.
Olivia.
Just like you thinking Cleo was a she,.. i have a Clara whom i was sure was a she but found out when it was a mature cat,..Clara is a he lol,..i didn't have to change the name as there is a village named Clara quite near.
Clara.