Play growl/noise okay?

Did some searches, but didn’t quite get the answer I wanted. Quick summary, girlfriend has dog, and got freaked out a bit when she realized she adopted a pit bull (mix I think). I put it in my hello post, but essentially, found a dog at shelter, thought he was so cute, they told her it was American Staffordshire Terrier, and I told her he was a pit (I was away for about 3 weeks when she got him). She went “oh crap”, kinda freaked for a bit, but he has been a breeze as far as training.

Anyway, I’ve done most of the training/shown her how the training he needs, and this forum has had great articles that backed up what I was telling her.

Quick background on the dog, 1 1/2 years old (roughly), she got from shelter four months ago. Very mild mannered dog. Doesn’t bark (once a month is his quota), doesn’t growl, quite a sucker for affection. Random people go over to her place and he just sucks up to everyone. Is not food aggressive, at all. He has picked up a chicken bone on a walk, and I’ve reached into his mouth to get it out. No fighting, no anything. He doesn’t quite have the drop command down. If I had said leave it he would have, but I didn’t see it in time. Still working on the drop with tasty items. He is fine with his ball lol.

He is not dog aggressive (I think). I’ve walked him and an old ladies Pomeranian got loose, comes charging over and yapping at him, and he was terrified. I had him sit, told the dog to go away, and the lady nabbed him. He does not like it when other dogs bark. He hangs out with her mother’s female dog when she had to go to a wedding for a few days, and they left them out together (despite what I said…it’s a lost cause there, the mother hasn’t ever disciplined her own dog, no crating, dog gets in pantry, it’s 10 years old now and is chaos incarnate) and he was fine. He meets random dogs on walks and is fine.

Right right, get off on target and raving about him, sorry. The only thing I’ve noticed is that when he was in the apartment dog park (don’t worry, it is only about 50 feet, and he never is in their with other dogs) and we play some times, he gets rowdy and gets loud playing. It doesn’t bother me, but spooked the GF, and asked if that was okay. Honestly, I didn’t know. He isn’t aggressive, and really, it just seemed like play to me. Not even a growl (or what I think of as one), just kinda of a short snarl/haha I’m playing sound. Wasn’t any teeth barred or anything either. The real question I have is it something I should try to get him to not do, or perfectly harmless? It seems harmless to me, but I don’t want it to turn into something more serious (and that last bit is essentially her question).

He also likes to throw his body around when he really gets into play, which seems fine to me, but she wonders if that is okay with other dogs or something that should be if possible stopped.

Thanks. It does seem pretty minor, but I figured I might as well ask it. At least she is concerned with the training now and asking questions. When I first met him, she wanted him to sleep in her bed, leave him out all day because keeping him in a crate was mean, etc. She has come around, and a lot of the informative posts here have vindicated my position. The last thing I want is for her to have an undisciplined dog, because he is quite the little ambassador as far as endearing people to the breed.

Except for cats. He wants to hunt them.