Does anyone know why my 6.1/2 month old homebred male pup. he seems to show more attention to 1 of 3 bitches that live with him? even when all 3 bithes came into season it was 95% of the time that he show all his attention to this one bitch? he pulls her about roughly always getting her behind the neck then he mounts her! he be mounting her approx from 12 weeks old!!!! its been approx 2 months since all bitches have had there seasons. but this one bitch he still keeps mounting her & she lets him by standing sumetime she stand until hes seems to have had enough or she snaps at him but this doesnt seem to bother him! just one thing  this bitch has been mated to couple of stud dogs that are proven and also she been recovered for free by the same dog. as she has falled to conceive. (all have tested and clear of any heredity conditions) also she been to vets for checks and they can't find any problem. one of the reason we kept homebred male is to try he as stud to cover her.  its seems differcult to stop him from doing what we kept him for . so any help on his behaviour or hers would be grateful. thanks

Sometimes humping is actually just over-excitement. He may enjoy playing with her more so than the other bitches.

My boy does this when playing, he's the same age, he finds it funny to get the upper hand on his sister.  He seems to know the big girls won't allow it.  However his mum came into season a few weeks ago and he wasn't remotely interested but my other girl is on her way or just in and he showed a little interest so will ahve to watch them.  He's not done any mounting behaviour with her but did have hi nose stuck to her bottom a few times.  They were playing together this morning.

He's still a baby so probably won't have any sexual urges yet, its a little young but be careful as there is a sall chance he can do things.

My girl who i mated would snap as part of the mating, unless she wasn't ready, she would tell him off for listening to her snapping and encourage him back, I'd never seen anything like it. :)