Housebroken Dog Keeps Pooping in House?

I recently moved in with a friend and ever since I moved in her dog has been pooping on the floor. It's a 4 year old Yorkie who is trained to use a pee pad. She has a huge spacious bathroom where she keeps the pee pad and keeps him in there during the day. Ever since I moved in the dog has been pooping everywhere on his pad, the floor, and everyday in the bathtub.

I thought the dog was doing it because it was scared of me, but I've never yelled at it or hit it and often play with it whenever I'm home. It seems to like me and always tries to play with me. Prior to me moving in the dog never did this and his owner's schedule hasn't changed so he's not in there longer than he used to be.