new puppy with 3 yr old male

Question
Thanks.  How do I approach controlling situations?  Do I seperate them, say "no" to the older dog, etc..  Right now they play a little, when the older feels like playing.  I can tell when they are just playing because the older one's tail is wagging.  The younger one constantly is nipping or biting at the older one and sometimes the older one will let out a bark and nip back, and I know he's probably telling the little one to get lost.  My older dog is very well disciplined and calm so this little bundle of energy is new to him so I think the pup gets on his nerves some.  Yesterday while he was eating the older one showed his K-9's just a little towards the pup.  I immediately called the older one's name and said no and he backed off and let the pup eat - from the same bowl even.  We bought another bowl but the older one will eat out of the new bowl and the younger one will eat out of the older one's bowl, and visa versa; so I don't know how to approach that.  Right now we just leave their food out all the time.
Thanks again,
Rick
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Followup To
Question -
We just purchased a male GS puppy.  We wanted to provide our 3 yr old male GS a playmate or buddy while we were at work, etc..  We heard that it wasn't a good idea to have two males, and we thought we purchased a female but now two days after we got the puppy we discovered it is a male.  I hate to take him back because our kids already love him and he is a great dog.  The problem is/may be, that our 3 yr old seems to be owning everything now; and I understand his behavior.  He hasn't been agressive towards the pup yet, aside from blocking the pup from his food bowl once and a quick bark of warning when the pup was "bugging" him.  But I have noticed that the 3 yr old now plays with bones and such that he never used to care about.  I don't want a bad situation so what should I do and what steps should I take to help them both, or should I take the pup back and get a female?  
Thanks for your time,
Answer -
HI RICK
IT IS ALWAYS BEST TO HAVE ONE OF EACH SO NO FIGHTING, TWO MALES GET VERY TERRITORIAL AND CAN LEARN TO FIGHT TERRIBLE.
IF YOU CAN KEEP IN CONTROL AND BE THE LEADER AND BOSS WHILE THIS PUPPY GROWS UP WITH THIS OLDER MALE, U MIGHT BE ABLE TO CONTROL THE SITUATION.?
I CAN NOT GUARANTEE THIS WILL HAPPEN WHEN IT MATURES, ONE IS GOING TO BE THE DOMINANT ONE EVIDENTUALLY.  THEN U WILL HAVE A REAL PROBLEM, BUT THEY CAN GROW UP TO BE BEST FRIENDS IF U DO NOT TOLERATE ANY NONSENSE AND CAN IN FACT BE THEIR LEADER AND MENTOR.?
THE OLDER MALE MIGHT TAKE TO THIS PUP AND BE BIG BROTHER, ENJOY THE COMPANY SO IT IS NOW YOUR JOB TO BRING UP THE PUPPY TO BE THE SAME WHEN OLDER, THAT NEITHER BECOMES DOMINANT OF THE OTHER.  GET THEM FIXED!!
BUT, ALWAYS IN BUYING A PLAYMATE GET THE OPPOSITE SEX TO ELIMINATE PROBLEMS.
I CAN RUN A PACK OF DOGS AND BE IN FULL CONTROL, BUT I AM A BREEDER AND A PRO, BUT I HAVE YET TO TURN MY NEW MALE, OTHELLO OUT WITH MY BREEDING STUD, GINO.  HE HAS ONLY BE HERE LITTLE OVER A MONTH AND DOES NOT LISTEN TO ENGLISH WELL YET AND I MIGHT NEVER TURN THEM TOGETHER TO EVER HAVE A DOG FIGHT HERE.?
BE IN CONTROL, WATCH EVERY SITUATION NOW AND KEEP LOTS OF TOYS, NYLABONES, GIVE DOGGIE BISCUITS AS REWARDS, NO PEOPLE FOOD AND DO NOT LET A FIGHT EVER HAPPEN.  GOOD LUCK AND VISIT MY SITE, LOOK AT THE PLAYFUL PAGE.

KIND REGARDS
PATT
WWW.SCHREKNHAUS.COM

Answer
HI
JUST GRAB A HUNK OF HAIR ON ITS BACK AND SAY NO.  LET THE OLDER DOG TEACH THE PUP TO STOP, IT WILL.
I JUST CAME UP FROM PLAYING WITH MY 7 PUPS AND THE ADULTS OUT AND THEY TEACH THEM NO!
LET HIM SHOW HIS TEETH WHEN EATING SO THE PUP KNOWS TO GO TO ITS OWN BOWEL.  WE PLAY MUSICAL CHAIRS HERE AT FEEDING TIME WHEN ALL EATS.  GILLION THE PUP GOES FROM ONE DISH TO ANOTHER AND THE ADULTS WALK AWAY, ONE MIGHT LIFT HER LIP.
JUST KEEP IN CONTROL, IF THE OLDER DOG IS NOT DOING BAD, LET IT TEACH THE PUP FOR A GOOD ADULT CAN DO BETTER THAN A HUMAN.

REGARDS
PATT
WWW.SCHREKNHAUS.COM