Is this a behaviour I need to train out of him or is it just playing?

I have a 7 week old male staffy x kelpie (8 weeks on Monday). I also have a 8 year old staffy female who is very timid and pretty much sleeps allllll day. My puppy however has earned the nickname piranha because he’s constantly trying to bite everything and will nip at your feet ect. I’ve read here that they get worse when they don’t get enough sleep and I’ve definitely learnt that when it gets bad I need to enforce a nap which he usually goes straight down when I do. Anyway the reason I’m posting is because when he plays with my adult dog he is constantly nipping at her face which she’s pretty good at dodging it but sometimes he does make contact for a couple of seconds and then lets go. As someone who has had their fingers in that mouth I know it hurts but she is so timid that she won’t even react so I don’t know if it’s hurting her. I got a video of it to show but just realised I can’t post media here. I doubt she will ever correct him because she just takes what she gets and looks unbothered all the time. Is this something I should stop him from doing or is it just playing? Part of me thinks if it’s hurting her or if he goes too far she will make it known but I also know how calm of a dog she is.