Chihuahuas are an awesome breed to own. They're smart, full of personality, and incredibly cute. However, an issue that is common with the breed is their tendency to latch on to their owner and hate anyone one else who comes near. While their protective nature is admirable, it can be frustrating when you have visitors or take your chi to an event with other dogs. This is how my Sonic was when I adopted him. After years of training, though, he is now about as friendly as any other dog breed. One way I helped train away his fierce loyalty was to simply pick him up whenever ever visitors stopped by and placed him in their arms so they could hold him. I would then praise him for allowing them to pet him. This let's your dog know that it is ok for him to seek attention from people other than you. Do this enough and eventually your chi will go up to other visitors on their own.