Is it permissible for a woman to insert semen from a strange man into her uterus with the permission of her husband?

It is not permissible to embark on this matter due to its violation of both Sharia and ethics, even if all parties consent. This is because it leads to the intermingling of lineages, which is one of the primary reasons for the prohibition of fornication. If a man's semen mixes with a woman's semen in the womb, a human being can be created, as Allah Almighty says: "So let man observe from what he was created. He was created from a flowing fluid, emerging from between the backbone and the ribs."