I have a 3 1/2 month old Beagle/Chihuahua/Dachshund puppy named Georgie who is having problems potty training.

Georgie will pee outside with no problem but will take awhile to poop if he does at all outside. He usually will wait until he gets inside. Also...he won't come when he's called. Even if I get down on the floor and call him with a treat or something he won't come to me. I try to be as nice as I can be to him and he's aggressive towards me. He snips at me and barks. But with my boyfriend (who raises his voice at Georgie) he slowly comes to him and wags his tail and does not bark or growl. What do I do to get him to obey me?