I have a miniature pincher and he only trusts 2 people unconditionally, me and my mom. He has learned to accept my mom's husband as someone who he tolerates and he is slowly learning to tolerate a few other people. He is very protecting of mom and constantly watches out for her. I am only second best in his book.
Mini Pins as a breed only trust and get attached to a small group of people and rarely let anyone else into their circle. I can pet his belly and play with his ears and pick him and cuddle with him but if someone else even went to pet him then he would snap and growl. He is true to his breed and is not a people dog.
Compare Diesel to my Saint Bernard puppy Elvis and you will get different results. When I first got him, it took him a while to get used to people and to fully trust in me. Now he is so excited to see me and to play and I could do anything to that dog and he wouldn't even flinch. He likes other people and as long as they give him an ice cube he is accepting of them.