Pluto has two Russian Blues. He was here before both of them - and started out bigger than them - of course now they are much bigger.
They all get along really pretty well. We have to make sure Pluto doesn't try and "discipline" the cats - as sometimes he will do that if food or the bed is involved. Otherwise - the give eachother buzz kisses - play with each other's toys.. and yes... sometimes Pluto thinks it's fun to hump Sweetie his private love kitty.

And... Sweetie lets him. SMH.
It can work.