Well, on the 1st day yes there were a few tussles, and he growls when playing alot (the insutrctor wasnt at all worried she said he is just vocal when playing, but the main thing was he was trying to, and succseeding in the end, mounting them.
Then the other night there were some other, older pupps there and one of them, about twice his size, straight away went for Billy, we eased them into playing together and good I thought he needs to be put in his place, they had a few tussles, i wasnt too worried but by the end of the night the bigger dog was letting my pup mount her also. I know this isnt sexual behaviour, hes only 12 weeks and was fixed before we got him. One other much bigger dog was there and Billy tried also to mount him, but this pup was 5 months old and twice the size and was having none of it, kept swatting him away, and Billy (my dog) was whimpering like a baby when he couldnt get his way.
Also if he is engrossed in play with one pup and another comes along, he barks and tries to shoo the other dog wanting to join the fun away. When he wants to join in on others playing he jumps on one of thier backs and, well, its embarrassing, but its like he says here i come, everyone do what I say. He also always manages to get in the position where the other dog is on its back and he is standing over them while playing.
I must say though that I have no Idea of what is NORMAL puppy play, rough or otherwise, maybe that is my problem, you know it takes a bit of getting use to all this bum sniffing and stuff. LOL. The instructor wasnt too concerned but she did say he was the dominant pup in the class, she didnt say that in a negative way, just sort of matter of fact.
The older dog idea would probably be a good place to start, I have a friend whos dogs would be perfect for that. They are very well trained, bigger, older and very social.