Shagging away merrily, suddenly, in last few days (not that his littermate seemed to mind at all).
They are both due to be castrated in 2.5 weeks (just short of 6 months, about as early as I can get them in for it).
Well the humping cease after testes removed, or is there a risk it become learned behaviour he never drops? Should I try to get him fixed sooner? I live in fear of the DC noticing & become fascinated with the kitty porn show (sigh).