Part beagle and tasmanian devil or something. Would love to see a pic. I hope he will turn out okay.

He's not too young to begin teaching him about 'self control'. One way to do that is to use NILIF techniques. You can google for 'NILIF' and read several of the pages to get an idea.

Basically he will learn that he gets attention if he sits and waits (for a few seconds anyway) initially. Later as his attention span improves, he will sit automatically for attention.

Don't indulge him. Have everyone in the family be consistent. If he walks up for attention have him sit first. (we all tend to pet automatically, this is not good for pushy pups expecting vending machines) Once he sits, the loving begins.

Sit is easiest to teach to pups via hand signals. That is a wee dime-thick piece of hot dog or tiny cube of cheese, held over his nose and with the hand moving toward the back of his skull will make him sit.

Pups use their mouths and paws to get attention. As he learns he must sit to get attention and that you are not 'love vending machines' that dispense on demand, he will learn more control.

When he does put his mouth on you, yelping like a ki-yi-yi-yi, screaming dog with a paw stuck in a closed door will impress most pups and make them pause. Everyone must be consistent. If you have kids not coordinated enough to be consistent, they need to be out of reach when the pup is not supervised. I have had one or two pups that thought the screaming bit was entertaining, and they would eyeball their victim with definite mischief in the eye and chomp again, as if we were squeak toys. With these pups, we used stronger methods to stop the squealing.

What that means is we put the entire exercise into THEIR control. If they want some fingers in their mouth, give it to them--- *generously* which means most of your fist too! No no... Not like you are punching them but if they go for fingers, let the hand slither like a wedge into the mouth too. The moment they gag, stop and take your hand out and ignore them. Usually it doesn't take many of these gag reflexes but all I'm suggesting here is that some pups may seem to enjoy making people yip and scream. (I learned this trick from a Labrador trainer who also knew some persistent pups).

What you really have going on is not just a mouthy problem however, it is probably going to become a lifetime issue of not having self control. NILIF is very gentle. It's like a mental boot camp. Reprogramming so that the dog thinks, sits, then patiently waits for attention. This will also pave the way to helping to prevent jumping up.