Yep, my boy will hump arms occasionally too... thankfully he has yet to discover the joys of leg-humping, and I hope he never does.
Many people will say it's a dominance thing - he's trying to assert himself as the boss of your BF. Some say they do it just because it feels good. Nikko tends to do it most when he's tired and crabby (but doesn't realize he's tired).
Either way, I say don't allow it at all. When he does it, I shove Nikko down and off of me just hard enough to knock him off his feet, and say "No humping!" then I will ignore him for a handful of seconds. His humping has lessened for sure, but it sill pops up occasionally (once a day or once every couple days). Hopefully after he's neutered, it'll lessen even more.
Good luck,
Lauren & Nikko |