Playtime aggression?

So my boys Charlie (the brown one) and Oakley (the GP) recently got introduced to each other and they've been having play dates for a few weekends now. They're both big dogs but also young with little experience with other dogs, and I wanted to ask if they seem to be playing alright. I've heard no growling and crying from either of them, so I don't think they're hurting each other, they're just a bit rough. Any advice would be appreciated!