That's it, really.
Clearly Things have changed very recently, as the boys have suddenly started wedging their noses into one another's scrotums, and Bigger Kitten has started attempting to mount Smaller (Wimpier) Kitten, though he's a bit crap at it. They're obviously starting to smell grown up and exciting.
They're having a pre-op weigh-in in two days' time and all being well, are being de-nutted next week, poor boys. Has anyone else got young male cats who are suddenly interested in one another like this, or are mine particularly perverse? 