Similar to "
hair of the dog" meaning a beer to cure a hangover, except "hair of the cat" typically means a second date, rendezvous, etc with a girl that you hung out with a few days before. Contrary to popular opinion, it does NOT mean just "sex". It can mean that you had an awesome date and want to see her again, that you've been missing her and
can't stop thinking about her, etc.
Or it can mean that you just haven't fucked your gf
in a few days and you're missing her pussy as much as you're missing her.