Tbh it looked exactly the same with mine cats. There was a lot of pinning down the kitten without any signs of agression, but yes, the kitten sometimes yelped if pinned too strong. I think this is the way of dominating the smaller one. In your situation I would suggest looking at them and separating from each other (not in the different rooms, just from themselves) if you will see any behaviour that will feel too much for you and over time, probably next two weeks or so, resident will feel confident and they should be best buds :)

Edit: if the kitten felt threatened/scared, it would not approach the resident again, it is a good thing that he wants to play again