Not expert, just adopted my first big dog, year old labradoodle who wasn’t getting enough time from his previous family - they had two kids and then had twins and right now he needs a lot of attention and training which they didn’t have the bandwidth for. Wonderful people though and they did the right thing finding us. He has a few barking and playing-too-rough-with-the-tiny-chihuahua-and-cats issues we are figuring out, but overall it’s always clear where it’s coming from when he’s misbehaving and he’s a good loving dog in the end. He’s also only been here slightly more than a month and I’m told it takes three before they’re really settled, so we have high hopes.
Is this when your parents aren’t home? Or when they’re around? Could mean different things. Some dogs tend to be one-person dogs who tolerate those who live with them and have no interest in anyone else. Breeds affect this kind of thing too.