hi,
as no one else has replied yet, i will

i dont allow any of my dogs to hump anything.... humping is a form of dominance, its what pups do to find out who is going to be the top dog so to speak. the top dog is allowed to hump

your little pepper is telling you that he is top dog over you!
if one of my pups do it i tell take them off and tell them a stern 'NO'! they soon get the message and the humping stops. if you dont do anything about it it will just keep happening IMO
my jack who is 14 weeks old tomorrow tried it on a bit when he first came but we havent had any humping for weeks now.