I bring my dogs to different kennels and 2 of these have left my dogs play with the other dogs. They both told me the same thing. When my female starts playing with the other dogs, my male will get rough with her and then mount her. It's like he's telling her "you're mine" or something. I've never seen him hump her or be rough with her so I find this really strange to hear. What's going on? Can he be jealous? Should I worry about this? They are 4 years old so I'm thinking that's the extent of his madness.