When I got Chops she was MAYBE half the size of my cocker spaniel. Now at 7 months, shes huge. They always played and rough housed but Chops quickly outgrew my Cocker, Lucky. They still go at is like theres no tomorrow, but not in a vicious or aggressive manner. In fact, Chops often lets Lucky "win" by rolling on her back and letting Lucky get on top of her belly. Should I discourage this behavior even though my AB "submits" to the smaller cocker? They chase each other around the yard and roll around pulling esch others ears and what not, but are always kissing and fine with each other when thy tire out. They also break it up whenever I tell them to. Any opinions? Thanks!