Our pups are now 4 months old. Dukie the boy pup has an obsession with Boo's nether regions. He will be neutered when he is 6 months old but in the mean time, is this normal?
I'd just keep a very careful eye on them and have one or both done as soon as it is healthy, smaller breeds reach sexual maturity quicker, my two are brother and sister were never left alone together, ever, season or no season, until he was neutered.