We have a little mixed puppy that's around 4 months old. She's a rescue and she's been with us a little under a week. Well, tonight my 10 year old son was rolling around on the ground with her and she started humping him. She was trying anyway. Is this dominate behavior? If so, how should it be handled? We believe she's a little pit mix. She's a big lover and pretty submissive as far as I can tell.