My glider seems to be overgroomimg. He also bights at his hands/paws and always scratches his side with his foot. He's also seemed to be getting tired faster and not eating as much.
I'm new, so should I be worried?
Is this just part of pueberty? I did see his gentalia for the first time a few days ago.

I wouldn't worry about overgrooming unless you are seeing bald spots. I've seen my gliders groom for 2 minutes or 1/2 hour. What do you consider to be getting tired faster? If he's new to you, a well check would be a good idea regardless.

yeah over grooming isnt a good thing. you should take him to the vet. you also need to get him a cagemate

Is he a lone glider?

He doesn't have a cage mate. When we got him people said they can die of lonelyness and depression unless you get them a buddy. We figured he would be fine because I don't sleep at night (that's a different story though). I'm with him the whole time he's awake- exept when I walk out of the room ,he probably needs his alone time too sometimes.

You can talk in glider-ese and groom that spot he can't grab? And run around together and cuddle all day long?

Sorry to come across snippy but you can't replace a glider companion, because you aren't a glider.

He's probably lonely and would benefit greatly from a companion.

Agreed- he needs a cagemate. A human can not replace another of their kind, even if you are up all night. It's not the same.