Big red flag here spiritus... I'm approaching this as much from a moms' view point as I am a trainer, so bear with me. Sneaking him in the house when your mom's not home is not going to correct the situtation. Mom needs to be on board with this. The dog needs to be in obedience training and he needs to have a consistent schedule. What will happen is you're now letting him know what he's been missing after having spent most of his life outdoors. You'll be able to sneak him in every once in awhile when mom' at work, but it won't be a consistent schedule. Once Hershey's begun to enjoy this, he'll learn to bark to get you to let him back in or become destructive out of frustration over being isolated and banished to the backyard again. (I.e digging holes in the yard) Also, you're letting him off leash too soon. Just one slip up and mom has a reason say "I told you so, he's to remain an outdoor dog!" Is there any way you can get mom to agree to a specific time frame each day that he's allowed inside for training, with sit, down, stay, off and leave it being taught, then some playtime and a walk thru the neighborhood before he's put back out on his tie out in the yard? A consistent schedule is important here, as well as moms' cooperation, or I see behavioral problems developing.