step-Mom wants you to be her sperm donator

As you know step-son, your step-father and i tried to have a step-son for a long time, I made some medical studies, everything is fine with me, but your step-father might be sterile. I been thinking about to search for a sperm donator but i want to this step-son be a real part of this family, i want it to have the same DNA. So it might sound crazy but i want you to be my sperm donator. The only thing i am ask you is to cum in here, and if you want I can help you during the whole process