Doxie behavior

Question
We recently got an 8-week old male doxie, Titan, (as a "brother") for our 6-month old male doxie, Goliath.  Titan is a very sweet puppy with a good temperament.  Goliath, on the other hand, has been showing some strange behavior since we brought Titan home.  For the most part, they play-fight and get along most of the time.  However, we have noticed that Goliath has been displaying jealous behavior.    He has also snarled at us a few times.  Nothing threatening, yet, but no one wants their dog to snarl at them.  He has also been giving us some "strange" looks.  I know that is vague, but I don't know how else to desribe it.  
Any advice would be helpful.  

Answer
Hi, I have a couple of questions before I can help with this.  
1.  Is Goliath neutered?
2.  Can you describe the events in as much detail as possible what was going on each time Golith snarled at you?
3.  When you say strange looks, is he staring at you or what?
4.  What has he done to the puppy (in as much detail as possible)?

Thanks,

Dawn