Do you have any specific reason to believe that Cynthia is not being truthful about her intent to not have a child of her own? Has she been dishonest about other issues in the relationship? In any case, it may be helpful for you to share your concerns with Cynthia. Tell Cynthia that you fear she might change her mind in the future and that you would not want her to be unhappy and unfulfilled, but that having a child with you is not an option.
It might be helpful for you to ask her to talk about her reasons or motivations for not wanting to have children. For example, one of the motives some childless-by-choice individuals cite is concern for overpopulation and a deep caring for the health of the planet. Other childfree individuals think they would not make a good parent or have a health condition in their family they do not wish to risk passing on to a child. Some childfree-by-choice adults simply enjoy the lifestyle and freedom that comes with not having the day-to-day responsibilities of having children.
Finally, have you considered getting a vasectomy? You might talk to your doctor about this option and discuss it with Cynthia. If she is hesitant about your getting a vasectomy, that may be indicative of a lack of certainty on her part about the decision to be childfree. On the other hand, if she says, “great idea,” that shows commitment to not having a child, at least with you as the biological father. There are no guarantees that Cynthia will not have a change of heart in the future, but you can at least assess if she is sincere in the present about not wanting to have a child.
Caroline Schacht has a master’s degree in home economics and another in sociology. She has been trained as a divorce mediator and a teacher at East Carolina University, specializing in courtship and marriage classes. She is the co-author of several textbooks, including "Choices in Relationships and Understanding Social Problems." She can be reached a cschacht@suddenlink.net.