Puppy refuses- potty question.

Brittanie • Ariel Diana Nichole was born 9/7/16😊 Pregnant with my 2nd 💕
I'm asking this more for my husbands dog he recently picked up, but I'm kind of curious at this point too! We got this little guy on Saturday. He's a sweetheart, and listens so well. He knows to sit when he wants a treat or his little stuffed doggy. When we tell him to go to sleep, he cuddles the stuffed animal and sleeps on his bed. BUT... He refuses to use the potty OUTSIDE almost 95% of the time. We will take him out with food and water, let him have at it (he has a food schedule), and sit outside with him for an hour or more to let him do his business and play around. He won't use the bathroom! But as soon as we go inside, he pees or poops in the floor, then KNOWS he's going to get in trouble for it. I'm so clueless. I've never had a puppy act like this. He's maybe 3-4 months old. Any advice or ideas ladies...? Thank you!