Just wanted to ask a question, our puppy Tedd likes to play with our older dog Rex. Tedd is the one who starts it by jumping up at Rex and nipping around his mouth etc. Sometimes Rex wants to play and sometimes not. But when they do Rex chases Tedd around and tries to get on his back but Tedd just rolls around. Is this normal? Rex doesn't bite or growl, they are both wagging their tails and when Rex stops, Tedd annoys him again to play. I get worried cuz Rex is a bit bigger than Tedd and that he might hurt him. But is this play okay or not?