This. I personally believe this is the true reason for his reluctance – right now he has right where he wants her. Living with him, but not really taking up space. If they get a house together, she will have a say. I think he likes her not having a say. Because as much as hesitating before a huge purchase like this is normal, the fact that she doesn't get to really customize the space in which she lives in, is not. Preferably, he would want to make space for her as she's his partner and he wants to share a life. Instead, it's the opposite – she is not just not taking space, she is actively getting rid of her own things.
This. I personally believe this is the true reason for his reluctance – right now he has right where he wants her. Living with him, but not really taking up space. If they get a house together, she will have a say. I think he likes her not having a say. Because as much as hesitating before a huge purchase like this is normal, the fact that she doesn't get to really customize the space in which she lives in, is not. Preferably, he would want to make space for her as she's his partner and he wants to share a life. Instead, it's the opposite – she is not just not taking space, she is actively getting rid of her own things.
I'd make your concerns known but I wouldn't try to convince him because that could just drive him away if he didn't ask for your opinion.
He's an adult and, as sad as it is, he's free to date his cheating ex if he wants.