I teach mouthy puppies to play with me with a toy only. They start biting, I get a toy and get them to play by wiggling it on the ground like a injured bunny. If they play toy, we play. If they launch at my flesh, I put them away (into a crate or behind a gate) for a few minutes. Then I offer the toy again.
You want to play? We play with toys, not flesh. If you don't want a toy, fine, I am not going to play or give you access to my skin.
Pretty quick they figure it out and start shoving toys at you instead of biting most of the time. Try it and see if it helps?