Hello everyone! I am new here. I have a 7 year old mix breed male dog who was potty trained, not neutered. We got a new female puppy for 7 months now. I noticed that my older dog is now back to peeing inside the house. He would go out for regular peeing and pooping outside but once he gets inside the house, he is gonna pee again (kind of marking everywhere). My puppy is very playful and would often want to play with my older dog which causes too much barking on my older one. Recently, they both became aggressive towards each other and we have to separate them as to not cause accidental harm. The aggression was like a switch that was turned on and every time they see each other. I love both of my dogs and doesn't want to give up on either one.