What is the test for determining whether a parent's best interests is to restrict access to a parent who lives in another parent's home?

Similarly, in MacGyver v. Richards, supra, at para. 38, Abella J.A. said: 38 The child's best interests must be assessed not from the perspective of the parent seeking to preserve access, but from that of the child entitled to the best environment possible. It is a mistake to look down at the child as a prize to be distributed, rather than from the child up to the parent as an adult to be accountable. This by no means eliminates the adult’s wishes from the equation; it means that those wishes cannot be accommodated. It is the child's right to see a parent with whom she does not live, rather than the parent's right to insist on access to that child. That access, its duration and quality, are regulated according to what is best for the child rather than what is best for the parent seeking access.