I find all dogs play different ways. My bulldog has a friend bulldog and when they get together they jump into the air and kind of smash their chests together. It is weird, but that is how they play. My dog doesn't do that with any other dog, just him.
Location also has a lot to do with it, most dogs will be more aggressive in their own home (or so I find).
Try taking them both out to the park or have him come to your place and see if it makes a difference.
Also, the more time they spend together the better they will be together.
Good luck!