The first bit sounded like grooming but the second half sounds like testing for food.
Whenever my gliders have groomed me it's been very gentle and little teeth if any. Mostly my gliders have sat down and just licked my finger for a good 3-5 minutes. Grooming shouldn't be painful.
But if he was actually trying to hurt you, or thought you were food, you'd know. Glider bits aren't fun, they have very sharp long teeth. From what you've described he definitely wasn't trying to hurt you or being mean.
Once your glider knows your smell they won't do that. Every glider owner goes through the "I'm not food" stage.